Planck (spacecraft)

<h2 id="objectives">Objectives</h2>
The mission had a wide variety of scientific aims, including:<a class="footnote-ref" id="fnref:1" href="#fn:1">1</a>

<ul><li>high resolution detections of both the total intensity and polarization of primordial <a href="/facts/Cosmic_microwave_background_radiation/ThB2HkLS">CMB</a> anisotropies,</li>
<li>creation of a catalogue of <a href="/facts/Galaxy_clusters/BhIEgbx8">galaxy clusters</a> through the <a href="/facts/Sunyaev%25E2%2580%2593Zel%2527dovich_effect/5o66v730">Sunyaev–Zel'dovich effect</a>,</li>
<li>observations of the <a href="/facts/Gravitational_lens/LmxzvLs8">gravitational lensing</a> of the CMB, as well as the integrated <a href="/facts/Sachs%25E2%2580%2593Wolfe_effect/ydR1IqB8">Sachs–Wolfe effect</a>,</li>
<li>observations of bright extragalactic radio (<a href="/facts/Active_galactic_nucleus/qT1owvXz">active galactic nuclei</a>) and infrared (dusty galaxy) sources,</li>
<li>observations of the <a href="/facts/Milky_Way/ulF6lccN">Milky Way</a>, including the <a href="/facts/Interstellar_medium/mokU0WEz">interstellar medium</a>, distributed <a href="/facts/Synchrotron_radiation/mTsSKmRz">synchrotron</a> emission and measurements of the Galactic <a href="/facts/Magnetic_field/Ta8Ev588">magnetic field</a>, and</li>
<li>studies of the <a href="/facts/Solar_System/QIcLSazQ">Solar System</a>, including <a href="/facts/Planet/rbPjE6Bx">planets</a>, <a href="/facts/Asteroid/g7Ulr1VB">asteroids</a>, <a href="/facts/Comet/w34utQCd">comets</a> and the <a href="/facts/Zodiacal_light/HqQjsaox">zodiacal light</a>.</li></ul>
Planck had a higher resolution and sensitivity than WMAP, allowing it to probe the power spectrum of the CMB to much smaller scales (×3). It also observed in nine <a href="/facts/Frequency/QUSbPaW8">frequency</a> bands rather than WMAP's five, with the goal of improving the astrophysical foreground models.
It is expected that most Planck measurements have been limited by how well foregrounds can be subtracted, rather than by the detector performance or length of the mission, a particularly important factor for the <a href="/facts/Polarization_(waves)/fP33m0eD">polarization</a> measurements.[needs update] The dominant foreground radiation depends on frequency, but could include synchrotron radiation from the Milky Way at low frequencies, and dust at high frequencies.[needs update]

<h2 id="instruments">Instruments</h2>

The spacecraft carries two instruments: the Low Frequency Instrument (LFI) and the High Frequency Instrument (HFI).<a class="footnote-ref" id="fnref:2" href="#fn:2">2</a> Both instruments can detect both the total intensity and <a href="/facts/Polarization_(waves)/fP33m0eD">polarization</a> of photons, and together cover a frequency range of nearly 830 GHz (from 30 to 857 GHz). The cosmic microwave background spectrum peaks at a frequency of 160.2 GHz.
Planck's passive and active cooling systems allow its instruments to maintain a temperature of −273.05 °C (−459.49 °F), or 0.1 °C above <a href="/facts/Absolute_zero/U3UyPl2K">absolute zero</a>.<a class="footnote-ref" id="fnref:3" href="#fn:3">3</a> From August 2009, Planck was the coldest known object in space, until its active coolant supply was exhausted in January 2012.<a class="footnote-ref" id="fnref:4" href="#fn:4">4</a>
NASA played a role in the development of this mission and contributes to the analysis of scientific data. Its <a href="/facts/Jet_Propulsion_Laboratory/zPXnxRBf">Jet Propulsion Laboratory</a> built components of the science instruments, including <a href="/facts/Bolometer/5YlzCoe8">bolometers</a> for the high-frequency instrument, a 20-kelvin <a href="/facts/Cryocooler/7cs7ygf2">cryocooler</a> for both the low- and high-frequency instruments, and amplifier technology for the low-frequency instrument.<a class="footnote-ref" id="fnref:5" href="#fn:5">5</a>

<h3>Low Frequency Instrument</h3>
<table><tbody><tr><th>Frequency(GHz)</th><th>Bandwidth(Δν/ν)</th><th>Resolution(arcmin)</th><th>Sensitivity (total intensity)ΔT/T, 14-month observation(10−6)</th><th>Sensitivity (polarization)ΔT/T, 14-month observation(10−6)</th></tr><tr><td>30</td><td>0.2</td><td>33</td><td>2.0</td><td>2.8</td></tr><tr><td>44</td><td>0.2</td><td>24</td><td>2.7</td><td>3.9</td></tr><tr><td>70</td><td>0.2</td><td>14</td><td>4.7</td><td>6.7</td></tr></tbody></table>
The LFI has three frequency bands, covering the range of 30–70 GHz, covering the microwave to infrared regions of the electromagnetic spectrum. The detectors use <a href="/facts/High-electron-mobility_transistor/CqUYlfxY">high-electron-mobility transistors</a>.<a class="footnote-ref" id="fnref:6" href="#fn:6">6</a>

<h3>High Frequency Instrument</h3>

<table><tbody><tr><th>Frequency(GHz)</th><th>Bandwidth(Δν/ν)</th><th>Resolution(arcmin)</th><th>Sensitivity (total intensity)ΔT/T, 14-month observation(10−6)</th><th>Sensitivity (polarization)ΔT/T, 14-month observation(10−6)</th></tr><tr><td>100</td><td>0.33</td><td>10</td><td>2.5</td><td>4.0</td></tr><tr><td>143</td><td>0.33</td><td>7.1</td><td>2.2</td><td>4.2</td></tr><tr><td>217</td><td>0.33</td><td>5.0</td><td>4.8</td><td>9.8</td></tr><tr><td>353</td><td>0.33</td><td>5.0</td><td>14.7</td><td>29.8</td></tr><tr><td>545</td><td>0.33</td><td>5.0</td><td>147</td><td>N/A</td></tr><tr><td>857</td><td>0.33</td><td>5.0</td><td>6700</td><td>N/A</td></tr></tbody></table>
The HFI was sensitive between 100 and 857 GHz, using 52 <a href="/facts/Bolometer/5YlzCoe8">bolometric</a> detectors, manufactured by JPL/Caltech,<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a> optically coupled to the telescope through cold optics, manufactured by Cardiff University's School of Physics and Astronomy,<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a> consisting of a triple horn configuration and optical filters, a similar concept to that used in the <a href="/facts/Archeops/9dGGz6vb">Archeops</a> balloon-borne experiment. These detection assemblies are divided into 6 frequency bands (centred at 100, 143, 217, 353, 545 and 857 GHz), each with a bandwidth of 33%. Of these six bands, only the lower four have the capability to measure the polarisation of incoming radiation; the two higher bands do not.<a class="footnote-ref" id="fnref:9" href="#fn:9">9</a>
On 13 January 2012, it was reported that the on-board supply of <a href="/facts/Helium-3/SmPC5oT3">helium-3</a> used in Planck's <a href="/facts/Dilution_refrigerator/s0RYbDAY">dilution refrigerator</a> had been exhausted, and that the HFI would become unusable within a few days.<a class="footnote-ref" id="fnref:10" href="#fn:10">10</a> By this date, Planck had completed five full scans of the CMB, exceeding its target of two. The LFI (cooled by <a href="/facts/Helium-4/vNsL5qhC">helium-4</a>) was expected to remain operational for another six to nine months.<a class="footnote-ref" id="fnref:11" href="#fn:11">11</a>

<h2 id="service-module">Service module</h2>

A common <a href="/facts/Service_module/79YA3cdQ">service module</a> (SVM) was designed and built by Thales Alenia Space in its <a href="/facts/Turin/PudIVEnr">Turin</a> plant, for both the <a href="/facts/Herschel_Space_Observatory/WgQTnYjK">Herschel Space Observatory</a> and Planck missions, combined into one single program.<a class="footnote-ref" id="fnref:12" href="#fn:12">12</a>
The overall cost is estimated to be €700 million for the Planck<a class="footnote-ref" id="fnref:13" href="#fn:13">13</a> and €1,100 million for the Herschel mission.<a class="footnote-ref" id="fnref:14" href="#fn:14">14</a> Both figures include their mission's spacecraft and payload, (shared) launch and mission expenses, and science operations.
Structurally, the Herschel and Planck SVMs are very similar. Both SVMs are octagonal in shape and each panel is dedicated to accommodate a designated set of warm units, while taking into account the dissipation requirements of the different warm units, of the instruments, as well as the spacecraft. On both spacecraft, a common design was used for the <a href="/facts/Avionics/F4gQJBJn">avionics</a>, attitude control and measurement (ACMS), command and data management (CDMS), power, and tracking, telemetry and command (TT&C) subsystems. All units on the SVM are redundant.

<h3>Power Subsystem</h3>
On each spacecraft, the power subsystem consists of a <a href="/facts/Solar_panels_on_spacecraft/js1dxpcr">solar array</a>, employing triple-junction <a href="/facts/Solar_cell/3L814UCC">solar cells</a>, a <a href="/facts/Battery_(electricity)/bqEpm4ue">battery</a> and the power control unit (PCU). The PCU is designed to interface with the 30 sections of each solar array, to provide a regulated 28 volt bus, to distribute this power via protected outputs, and to handle the battery charging and discharging.
For Planck, the circular solar array is fixed on the bottom of the satellite, always facing the Sun as the satellite rotates on its vertical axis.

<h3>Attitude and Orbit Control</h3>
This function is performed by the attitude control computer (ACC), which is the platform for the attitude control and measurement subsystem (ACMS). It was designed to fulfil the pointing and slewing requirements of the Herschel and Planck payloads.
The Planck satellite <a href="/facts/Rotation/yChkz49x">rotates</a> at one revolution per minute, with an aim of an absolute pointing error less than 37 arc-minutes. As Planck is also a survey platform, there is the additional requirement for pointing reproducibility error less than 2.5 arc-minutes over 20 days.
The main line-of-sight sensor in both Herschel and Planck is the <a href="/facts/Star_tracker/bHeWMhcq">star tracker</a>.

<h2 id="launch-and-orbit">Launch and orbit</h2>

The satellite was successfully launched, along with the <a href="/facts/Herschel_Space_Observatory/WgQTnYjK">Herschel Space Observatory</a>, at 13:12:02 UTC on 14 May 2009 aboard an <a href="/facts/Ariane_5/H78wlLG4">Ariane 5 ECA</a> heavy launch vehicle from the <a href="/facts/Guiana_Space_Centre/hp6TSJ6W">Guiana Space Centre</a>. The launch placed the craft into a very elliptical orbit (<a href="/facts/Periapsis/VaL6ow9w">perigee</a>: 270 km [170 mi], <a href="/facts/Apapsis/VaL6ow9w">apogee</a>: more than 1,120,000 km [700,000 mi]), bringing it near the <a href="/facts/Lagrange_point/XCAN4o3P">L2</a> Lagrangian point of the <a href="/facts/List_of_objects_at_Lagrangian_points/unIVKbu9">Earth-Sun system</a>, 1,500,000 kilometres (930,000 mi) from the Earth.
The manoeuvre to inject Planck into its final orbit around <a href="/facts/Lagrange_point/XCAN4o3P">L2</a> was successfully completed on 3 July 2009, when it entered a <a href="/facts/Lissajous_orbit/qgxn5sUn">Lissajous orbit</a> with a 400,000 km (250,000 mi) radius around the <a href="/facts/Lagrange_point/XCAN4o3P">L2</a> Lagrangian point.<a class="footnote-ref" id="fnref:15" href="#fn:15">15</a> The temperature of the High Frequency Instrument reached just a tenth of a degree above absolute zero (0.1 <a href="/facts/Kelvin/E3trzC4C">K</a>) on 3 July 2009, placing both the Low Frequency and High Frequency Instruments within their cryogenic operational parameters, making Planck fully operational.<a class="footnote-ref" id="fnref:16" href="#fn:16">16</a>

<h2 id="decommissioning">Decommissioning</h2>
In January 2012 the HFI exhausted its supply of liquid helium, causing the detector temperature to rise and rendering the HFI unusable. The LFI continued to be used until science operations ended on 3 October 2013. The spacecraft performed a manoeuvre on 9 October to move it away from Earth and its <a href="/facts/Lagrange_point/XCAN4o3P">L2 point</a>, placing it into a <a href="/facts/Heliocentric_orbit/b4zMv2jE">heliocentric orbit</a>, while payload deactivation occurred on 19 October. Planck was commanded on 21 October to exhaust its remaining fuel supply; <a href="/facts/Passivation_(spacecraft)/JcxJMEFx">passivation</a> activities were conducted later, including battery disconnection and the disabling of protection mechanisms.<a class="footnote-ref" id="fnref:17" href="#fn:17">17</a> The final deactivation command, which switched off the spacecraft's transmitter, was sent to Planck on 23 October 2013 at 12:10:27 UTC.<a class="footnote-ref" id="fnref:18" href="#fn:18">18</a>

<h2 id="results">Results</h2>

Planck started its First All-Sky Survey on 13 August 2009.<a class="footnote-ref" id="fnref:19" href="#fn:19">19</a> In September 2009, the <a href="/facts/European_Space_Agency/L8YRNV0C">European Space Agency</a> announced the preliminary results from the Planck First Light Survey, which was performed to demonstrate the stability of the instruments and the ability to calibrate them over long periods. The results indicated that the data quality is excellent.<a class="footnote-ref" id="fnref:20" href="#fn:20">20</a>
On 15 January 2010 the mission was extended by 12 months, with observation continuing until at least the end of 2011. After the successful conclusion of the First Survey, the spacecraft started its Second All Sky Survey on 14 February 2010. The last observations for the Second All Sky Survey were made on 28 May 2010.<a class="footnote-ref" id="fnref:21" href="#fn:21">21</a>
Some planned pointing list data from 2009 has been released publicly, along with a video visualization of the surveyed sky.<a class="footnote-ref" id="fnref:22" href="#fn:22">22</a>
On 17 March 2010, the first Planck photos were published, showing dust concentration within 500 light years from the Sun.<a class="footnote-ref" id="fnref:23" href="#fn:23">23</a><a class="footnote-ref" id="fnref:24" href="#fn:24">24</a>
On 5 July 2010, the Planck mission delivered its first all-sky image.<a class="footnote-ref" id="fnref:25" href="#fn:25">25</a>
The first public scientific result of Planck is the Early-Release Compact-Source Catalogue, released during the January 2011 Planck conference in Paris.<a class="footnote-ref" id="fnref:26" href="#fn:26">26</a><a class="footnote-ref" id="fnref:27" href="#fn:27">27</a>
On 5 May 2014 a map of the galaxy's magnetic field created using Planck was published.<a class="footnote-ref" id="fnref:28" href="#fn:28">28</a>
The Planck team and <a href="/facts/Principal_investigator/GXE6ILvW">principal investigators</a> <a href="/facts/Nazzareno_Mandolesi/0DVJdYr4">Nazzareno Mandolesi</a> and <a href="/facts/Jean-Loup_Puget/B6QaAVxU">Jean-Loup Puget</a> shared the 2018 <a href="/facts/Gruber_Prize_in_Cosmology/PsS9WcEg">Gruber Prize in Cosmology</a>.<a class="footnote-ref" id="fnref:29" href="#fn:29">29</a> Puget was also awarded the 2018 <a href="/facts/Shaw_Prize/t2DX62Yg">Shaw Prize</a> in Astronomy.<a class="footnote-ref" id="fnref:30" href="#fn:30">30</a>

<h3>2013 data release</h3>
On 21 March 2013, the European-led research team behind the Planck cosmology probe released the mission's all-sky map of the cosmic microwave background.<a class="footnote-ref" id="fnref:31" href="#fn:31">31</a><a class="footnote-ref" id="fnref:32" href="#fn:32">32</a> This map suggests the Universe is slightly older than thought: according to the map, subtle fluctuations in temperature were imprinted on the deep sky when the Universe was about 370,000 years old. The imprint reflects ripples that arose as early in the existence of the Universe as the first nonillionth (10−30) of a second. It is theorised that these ripples gave rise to the present vast <a href="/facts/Cosmic_web/CdTGMdsp">cosmic web</a> of <a href="/facts/Galaxy_clusters/BhIEgbx8">galactic clusters</a> and <a href="/facts/Dark_matter/y5HgX55N">dark matter</a>. The 2013 release found an asymmetry in the statistics of the CMB with respect to viewing angle in the sky, determining that "deviations from isotropy have been found and demonstrated to be robust against component separation algorithm, mask choice and frequency dependence",<a class="footnote-ref" id="fnref:33" href="#fn:33">33</a> more commonly known as the <a href="/facts/Axis_of_evil_(cosmology)/CuClrlDv">Axis of evil (cosmology)</a>. According to the team, the Universe is 13.798±0.037 billion-years-old, and contains 4.82%±0.05% ordinary matter, 26.8%±0.4% dark matter and 69%±1% <a href="/facts/Dark_energy/6bWIYewA">dark energy</a>.<a class="footnote-ref" id="fnref:34" href="#fn:34">34</a><a class="footnote-ref" id="fnref:35" href="#fn:35">35</a><a class="footnote-ref" id="fnref:36" href="#fn:36">36</a> The <a href="/facts/Hubble_constant/FJYfELCP">Hubble constant</a> was also measured to be 67.80±0.77 (km/s)/Mpc.<a class="footnote-ref" id="fnref:37" href="#fn:37">37</a><a class="footnote-ref" id="fnref:38" href="#fn:38">38</a><a class="footnote-ref" id="fnref:39" href="#fn:39">39</a><a class="footnote-ref" id="fnref:40" href="#fn:40">40</a><a class="footnote-ref" id="fnref:41" href="#fn:41">41</a>

<a href="/facts/Lambda-CDM_model/DmlhJHQU">Cosmological parameters</a> from 2013 Planck results<a class="footnote-ref" id="fnref:42" href="#fn:42">42</a><a class="footnote-ref" id="fnref:43" href="#fn:43">43</a><table><tbody><tr><th>Parameter</th><th>Symbol</th><th>Planck Best fit</th><th>Planck 68% limits</th><th>Planck+<a href="/facts/Gravitational_lens/LmxzvLs8">lensing</a> Best fit</th><th>Planck+lensing 68% limits</th><th>Planck+<a href="/facts/WMAP/UUJWfy0U">WP</a> Best fit</th><th>Planck+WP 68% limits</th><th>Planck+WP +HighL Best fit</th><th>Planck+WP +HighL 68% limits</th><th>Planck+lensing +WP+highL Best fit</th><th>Planck+lensing +WP+highL 68% limits</th><th>Planck+WP +highL+<a href="/facts/Baryon_acoustic_oscillations/yVM31Wel">BAO</a> Best fit</th><th>Planck+WP +highL+BAO 68% limits</th></tr><tr><td><a href="/facts/Baryon/QFwAUWK2">Baryon</a> density</td><td> Ω b h 2 {\displaystyle \Omega _{b}h^{2}} </td><td>0.022068</td><td>0.02207±0.00033</td><td>0.022242</td><td>0.02217±0.00033</td><td>0.022032</td><td>0.02205±0.00028</td><td>0.022069</td><td>0.02207±0.00027</td><td>0.022199</td><td>0.02218±0.00026</td><td>0.022161</td><td>0.02214±0.00024</td></tr><tr><td>Cold <a href="/facts/Dark_matter/y5HgX55N">dark matter</a> density</td><td> Ω c h 2 {\displaystyle \Omega _{c}h^{2}} </td><td>0.12029</td><td>0.1196±0.0031</td><td>0.11805</td><td>0.1186±0.0031</td><td>0.12038</td><td>0.1199±0.0027</td><td>0.12025</td><td>0.1198±0.0026</td><td>0.11847</td><td>0.1186±0.0022</td><td>0.11889</td><td>0.1187±0.0017</td></tr><tr><td>100x approximation to rs / DA (CosmoMC)</td><td> 100 θ M C {\displaystyle 100\,\theta _{MC}} </td><td>1.04122</td><td>1.04132±0.00068</td><td>1.04150</td><td>1.04141±0.00067</td><td>1.04119</td><td>1.04131±0.00063</td><td>1.04130</td><td>1.04132±0.00063</td><td>1.04146</td><td>1.04144±0.00061</td><td>1.04148</td><td>1.04147±0.00056</td></tr><tr><td><a href="/facts/Thomson_scattering/hUj6gSgB">Thomson scattering</a> <a href="/facts/Optical_depth/XQwtIdFH">optical depth</a> due to <a href="/facts/Reionization/tfqf1Ny9">reionization</a></td><td> τ {\displaystyle \tau } </td><td>0.0925</td><td>0.097±0.038</td><td>0.0949</td><td>0.089±0.032</td><td>0.0925</td><td>0.089+0.012−0.014</td><td>0.0927</td><td>0.091+0.013−0.014</td><td>0.0943</td><td>0.090+0.013−0.014</td><td>0.0952</td><td>0.092±0.013</td></tr><tr><td>Power spectrum of curvature perturbations</td><td> ln ⁡ ( 10 10 A s ) {\displaystyle \ln(10^{10}A_{s})} </td><td>3.098</td><td>3.103±0.072</td><td>3.098</td><td>3.085±0.057</td><td>3.0980</td><td>3.089+0.024−0.027</td><td>3.0959</td><td>3.090±0.025</td><td>3.0947</td><td>3.087±0.024</td><td>3.0973</td><td>3.091±0.025</td></tr><tr><td>Scalar spectral index</td><td> n s {\displaystyle n_{s}} </td><td>0.9624</td><td>0.9616±0.0094</td><td>0.9675</td><td>0.9635±0.0094</td><td>0.9619</td><td>0.9603±0.0073</td><td>0.9582</td><td>0.9585±0.0070</td><td>0.9624</td><td>0.9614±0.0063</td><td>0.9611</td><td>0.9608±0.0054</td></tr><tr><td><a href="/facts/Hubble%2527s_constant/FJYfELCP">Hubble's constant</a> (km Mpc−1 s−1)</td><td> H 0 {\displaystyle H_{0}} </td><td>67.11</td><td>67.4±1.4</td><td>68.14</td><td>67.9±1.5</td><td>67.04</td><td>67.3±1.2</td><td>67.15</td><td>67.3±1.2</td><td>67.94</td><td>67.9±1.0</td><td>67.77</td><td>67.80±0.77</td></tr><tr><td><a href="/facts/Dark_energy/6bWIYewA">Dark energy</a> density</td><td> Ω Λ {\displaystyle \Omega _{\Lambda }} </td><td>0.6825</td><td>0.686±0.020</td><td>0.6964</td><td>0.693±0.019</td><td>0.6817</td><td>0.685+0.018−0.016</td><td>0.6830</td><td>0.685+0.017−0.016</td><td>0.6939</td><td>0.693±0.013</td><td>0.6914</td><td>0.692±0.010</td></tr><tr><td>Density fluctuations at 8h−1 Mpc</td><td> σ 8 {\displaystyle \sigma _{8}} </td><td>0.8344</td><td>0.834±0.027</td><td>0.8285</td><td>0.823±0.018</td><td>0.8347</td><td>0.829±0.012</td><td>0.8322</td><td>0.828±0.012</td><td>0.8271</td><td>0.8233±0.0097</td><td>0.8288</td><td>0.826±0.012</td></tr><tr><td><a href="/facts/Redshift/Qfl4VjDF">Redshift</a> of <a href="/facts/Reionization/tfqf1Ny9">reionization</a></td><td> z r e {\displaystyle z_{re}} </td><td>11.35</td><td>11.4+4.0−2.8</td><td>11.45</td><td>10.8+3.1−2.5</td><td>11.37</td><td>11.1±1.1</td><td>11.38</td><td>11.1±1.1</td><td>11.42</td><td>11.1±1.1</td><td>11.52</td><td>11.3±1.1</td></tr><tr><td><a href="/facts/Age_of_the_Universe/BaByputq">Age of the Universe</a> (Gy)</td><td> t 0 {\displaystyle t_{0}} </td><td>13.819</td><td>13.813±0.058</td><td>13.784</td><td>13.796±0.058</td><td>13.8242</td><td>13.817±0.048</td><td>13.8170</td><td>13.813±0.047</td><td>13.7914</td><td>13.794±0.044</td><td>13.7965</td><td>13.798±0.037</td></tr><tr><td>100× angular scale of sound horizon at last-scattering</td><td> 100 θ ∗ {\displaystyle 100\,\theta _{*}} </td><td>1.04139</td><td>1.04148±0.00066</td><td>1.04164</td><td>1.04156±0.00066</td><td>1.04136</td><td>1.04147±0.00062</td><td>1.04146</td><td>1.04148±0.00062</td><td>1.04161</td><td>1.04159±0.00060</td><td>1.04163</td><td>1.04162±0.00056</td></tr><tr><td>Comoving size of the sound horizon at z = zdrag</td><td> r d r a g {\displaystyle r_{drag}} </td><td>147.34</td><td>147.53±0.64</td><td>147.74</td><td>147.70±0.63</td><td>147.36</td><td>147.49±0.59</td><td>147.35</td><td>147.47±0.59</td><td>147.68</td><td>147.67±0.50</td><td>147.611</td><td>147.68±0.45</td></tr></tbody></table>

<h3>2015 data release</h3>
Results from an analysis of Planck's full mission were made public on 1 December 2014 at a conference in <a href="/facts/Ferrara/667uBfAc">Ferrara</a>, Italy.<a class="footnote-ref" id="fnref:44" href="#fn:44">44</a> A full set of papers detailing the mission results were released in February 2015.<a class="footnote-ref" id="fnref:45" href="#fn:45">45</a> Some of the results include:

<ul><li>More agreement with previous WMAP results on parameters such as the density and distribution of matter in the Universe, as well as more accurate results with less margin of error.</li>
<li>Confirmation of the Universe having a 26% content of dark matter. These results also raise related questions about the <a href="/facts/Positron/HgV4zBzA">positron</a> excess over <a href="/facts/Electron/L0KBo5cW">electrons</a> detected by the <a href="/facts/Alpha_Magnetic_Spectrometer/lcd9kQwf">Alpha Magnetic Spectrometer</a>, an experiment on the <a href="/facts/International_Space_Station/VNPUBz9m">International Space Station</a>. Previous research suggested that positrons could be created by the collision of dark matter particles, which could only occur if the probability of dark matter collisions is significantly higher now than in the early Universe. Planck data suggests that the probability of such collisions must remain constant over time to account for the structure of the Universe, negating the previous theory.</li>
<li>Validation of the simplest models of <a href="/facts/Inflation_(cosmology)/SujXx3aD">inflation</a>, thus giving the <a href="/facts/Lambda-CDM_model/DmlhJHQU">Lambda-CDM model</a> stronger support.</li>
<li>That there are likely only three types of <a href="/facts/Neutrino/yGWVfSg2">neutrinos</a>, with a fourth proposed <a href="/facts/Sterile_neutrino/5604ofcP">sterile neutrino</a> unlikely to exist.</li></ul>
Project scientists worked too with <a href="/facts/BICEP2/NTWI994B">BICEP2</a> scientists to release joint research in 2015 answering whether a signal detected by BICEP2 was evidence of primordial <a href="/facts/Gravitational_wave/4XWN3NtG">gravitational waves</a>, or was simple <a href="/facts/Background_noise/Vw1Fd6Nx">background noise</a> from dust in the Milky Way galaxy.<a class="footnote-ref" id="fnref:46" href="#fn:46">46</a> Their results suggest the latter.<a class="footnote-ref" id="fnref:47" href="#fn:47">47</a>

<a href="/facts/Lambda-CDM_model/DmlhJHQU">Cosmological parameters</a> from 2015 Planck results<a class="footnote-ref" id="fnref:48" href="#fn:48">48</a><a class="footnote-ref" id="fnref:49" href="#fn:49">49</a><table><tbody><tr><th>Parameter</th><th>Symbol</th><th>TT+lowP 68% limits</th><th>TT+lowP +lensing 68% limits</th><th>TT+lowP +lensing+ext 68% limits</th><th>TT,TE,EE+lowP 68% limits</th><th>TT,TE,EE+lowP +lensing 68% limits</th><th>TT,TE,EE+lowP +lensing+ext 68% limits</th></tr><tr><td><a href="/facts/Baryon/QFwAUWK2">Baryon</a> density</td><td> Ω b h 2 {\displaystyle \Omega _{b}h^{2}} </td><td>0.02222±0.00023</td><td>0.02226±0.00023</td><td>0.02227±0.00020</td><td>0.02225±0.00016</td><td>0.02226±0.00016</td><td>0.02230±0.00014</td></tr><tr><td>Cold <a href="/facts/Dark_matter/y5HgX55N">dark matter</a> density</td><td> Ω c h 2 {\displaystyle \Omega _{c}h^{2}} </td><td>0.1197±0.0022</td><td>0.1186±0.0020</td><td>0.1184±0.0012</td><td>0.1198±0.0015</td><td>0.1193±0.0014</td><td>0.1188±0.0010</td></tr><tr><td>100x approximation to rs / DA (CosmoMC)</td><td> 100 θ M C {\displaystyle 100\,\theta _{MC}} </td><td>1.04085±0.00047</td><td>1.04103±0.00046</td><td>1.04106±0.00041</td><td>1.04077±0.00032</td><td>1.04087±0.00032</td><td>1.04093±0.00030</td></tr><tr><td><a href="/facts/Thomson_scattering/hUj6gSgB">Thomson scattering</a> <a href="/facts/Optical_depth/XQwtIdFH">optical depth</a> due to <a href="/facts/Reionization/tfqf1Ny9">reionization</a></td><td> τ {\displaystyle \tau } </td><td>0.078±0.019</td><td>0.066±0.016</td><td>0.067±0.013</td><td>0.079±0.017</td><td>0.063±0.014</td><td>0.066±0.012</td></tr><tr><td>Power spectrum of curvature perturbations</td><td> ln ⁡ ( 10 10 A s ) {\displaystyle \ln(10^{10}A_{s})} </td><td>3.089±0.036</td><td>3.062±0.029</td><td>3.064±0.024</td><td>3.094±0.034</td><td>3.059±0.025</td><td>3.064±0.023</td></tr><tr><td>Scalar spectral index</td><td> n s {\displaystyle n_{s}} </td><td>0.9655±0.0062</td><td>0.9677±0.0060</td><td>0.9681±0.0044</td><td>0.9645±0.0049</td><td>0.9653±0.0048</td><td>0.9667±0.0040</td></tr><tr><td><a href="/facts/Hubble%2527s_constant/FJYfELCP">Hubble's constant</a> (km Mpc−1 s−1)</td><td> H 0 {\displaystyle H_{0}} </td><td>67.31±0.96</td><td>67.81±0.92</td><td>67.90±0.55</td><td>67.27±0.66</td><td>67.51±0.64</td><td>67.74±0.46</td></tr><tr><td><a href="/facts/Dark_energy/6bWIYewA">Dark energy</a> density</td><td> Ω Λ {\displaystyle \Omega _{\Lambda }} </td><td>0.685±0.013</td><td>0.692±0.012</td><td>0.6935±0.0072</td><td>0.6844±0.0091</td><td>0.6879±0.0087</td><td>0.6911±0.0062</td></tr><tr><td>Matter density</td><td> Ω m {\displaystyle \Omega _{m}} </td><td>0.315±0.013</td><td>0.308±0.012</td><td>0.3065±0.0072</td><td>0.3156±0.0091</td><td>0.3121±0.0087</td><td>0.3089±0.0062</td></tr><tr><td>Density fluctuations at 8h−1 Mpc</td><td> σ 8 {\displaystyle \sigma _{8}} </td><td>0.829±0.014</td><td>0.8149±0.0093</td><td>0.8154±0.0090</td><td>0.831±0.013</td><td>0.8150±0.0087</td><td>0.8159±0.0086</td></tr><tr><td><a href="/facts/Redshift/Qfl4VjDF">Redshift</a> of <a href="/facts/Reionization/tfqf1Ny9">reionization</a></td><td> z r e {\displaystyle z_{re}} </td><td>9.9+1.8−1.6</td><td>8.8+1.7−1.4</td><td>8.9+1.3−1.2</td><td>10.0+1.7−1.5</td><td>8.5+1.4−1.2</td><td>8.8+1.2−1.1</td></tr><tr><td><a href="/facts/Age_of_the_Universe/BaByputq">Age of the Universe</a> (Gy)</td><td> t 0 {\displaystyle t_{0}} </td><td>13.813±0.038</td><td>13.799±0.038</td><td>13.796±0.029</td><td>13.813±0.026</td><td>13.807±0.026</td><td>13.799±0.021</td></tr><tr><td>Redshift at <a href="/facts/Decoupling_(cosmology)/Kj6FbgLf">decoupling</a></td><td> z ∗ {\displaystyle z_{*}} </td><td>1090.09±0.42</td><td>1089.94±0.42</td><td>1089.90±0.30</td><td>1090.06±0.30</td><td>1090.00±0.29</td><td>1089.90±0.23</td></tr><tr><td>Comoving size of the sound horizon at z = z*</td><td> r ∗ {\displaystyle r_{*}} </td><td>144.61±0.49</td><td>144.89±0.44</td><td>144.93±0.30</td><td>144.57±0.32</td><td>144.71±0.31</td><td>144.81±0.24</td></tr><tr><td>100× angular scale of sound horizon at last-scattering</td><td> 100 θ ∗ {\displaystyle 100\,\theta _{*}} </td><td>1.04105±0.00046</td><td>1.04122±0.00045</td><td>1.04126±0.00041</td><td>1.04096±0.00032</td><td>1.04106±0.00031</td><td>1.04112±0.00029</td></tr><tr><td>Redshift with baryon-drag optical depth = 1</td><td> z d r a g {\displaystyle z_{drag}} </td><td>1059.57±0.46</td><td>1059.57±0.47</td><td>1059.60±0.44</td><td>1059.65±0.31</td><td>1059.62±0.31</td><td>1059.68±0.29</td></tr><tr><td>Comoving size of the sound horizon at z = zdrag</td><td> r d r a g {\displaystyle r_{drag}} </td><td>147.33±0.49</td><td>147.60±0.43</td><td>147.63±0.32</td><td>147.27±0.31</td><td>147.41±0.30</td><td>147.50±0.24</td></tr><tr><td>Legend</td><td colspan="7"><ul><li>68% limits: Parameter 68% <a href="/facts/Confidence_interval/NS8mG5UE">confidence limits</a> for the base <a href="/facts/Lambda-CDM_model/DmlhJHQU">ΛCDM model</a></li><li>TT, TE, EE: Planck <a href="/facts/Cosmic_microwave_background/ThB2HkLS">Cosmic microwave background</a> (CMB) <a href="/facts/Spectral_density/q3Rfs7b0">power spectra</a>; here TT represents temperature power spectrum, TE is temperature-polarization cross spectrum, and EE is polarisation power spectrum.</li><li>lowP: Planck <a href="/facts/Polarization_(waves)/fP33m0eD">polarization</a> data in the low-ℓ likelihood</li><li>lensing: CMB <a href="/facts/Gravitational_lens/LmxzvLs8">lensing</a> reconstruction</li><li>ext: External data (BAO+JLA+H0). BAO: <a href="/facts/Baryon_acoustic_oscillations/yVM31Wel">Baryon acoustic oscillations</a>, JLA: Joint <a href="/facts/Light_curve/zN0wdtaR">Light-curve</a> Analysis (of supernovae), H0: <a href="/facts/Hubble%2527s_law/FJYfELCP">Hubble constant</a></li></ul></td></tr></tbody></table>

<h3>2018 final data release</h3>

<a href="/facts/Lambda-CDM_model/DmlhJHQU">Cosmological parameters</a> from 2018 Planck results<a class="footnote-ref" id="fnref:50" href="#fn:50">50</a><a class="footnote-ref" id="fnref:51" href="#fn:51">51</a><table><tbody><tr><th>Parameter</th><th>Symbol</th><th>TT+lowE 68% limits</th><th>TE+lowE 68% limits</th><th>EE+lowE 68% limits</th><th>TT,TE,EE+lowE 68% limits</th><th>TT,TE,EE+lowE +lensing 68% limits</th><th>TT,TE,EE+lowE +lensing+BAO 68% limits</th></tr><tr><td><a href="/facts/Baryon/QFwAUWK2">Baryon</a> density</td><td> Ω b h 2 {\displaystyle \Omega _{b}h^{2}} </td><td>0.02212±0.00022</td><td>0.02249±0.00025</td><td>0.0240±0.0012</td><td>0.02236±0.00015</td><td>0.02237±0.00015</td><td>0.02242±0.00014</td></tr><tr><td>Cold <a href="/facts/Dark_matter/y5HgX55N">dark matter</a> density</td><td> Ω c h 2 {\displaystyle \Omega _{c}h^{2}} </td><td>0.1206±0.0021</td><td>0.1177±0.0020</td><td>0.1158±0.0046</td><td>0.1202±0.0014</td><td>0.1200±0.0012</td><td>0.11933±0.00091</td></tr><tr><td>100x approximation to rs / DA (CosmoMC)</td><td> 100 θ M C {\displaystyle 100\,\theta _{MC}} </td><td>1.04077±0.00047</td><td>1.04139±0.00049</td><td>1.03999±0.00089</td><td>1.04090±0.00031</td><td>1.04092±0.00031</td><td>1.04101±0.00029</td></tr><tr><td><a href="/facts/Thomson_scattering/hUj6gSgB">Thomson scattering</a> <a href="/facts/Optical_depth/XQwtIdFH">optical depth</a> due to <a href="/facts/Reionization/tfqf1Ny9">reionization</a></td><td> τ {\displaystyle \tau } </td><td>0.0522±0.0080</td><td>0.0496±0.0085</td><td>0.0527±0.0090</td><td>0.0544+0.0070−0.0081</td><td>0.0544±0.0073</td><td>0.0561±0.0071</td></tr><tr><td>Power spectrum of curvature perturbations</td><td> ln ⁡ ( 10 10 A s ) {\displaystyle \ln(10^{10}A_{s})} </td><td>3.040±0.016</td><td>3.018+0.020−0.018</td><td>3.052±0.022</td><td>3.045±0.016</td><td>3.044±0.014</td><td>3.047±0.014</td></tr><tr><td>Scalar spectral index</td><td> n s {\displaystyle n_{s}} </td><td>0.9626±0.0057</td><td>0.967±0.011</td><td>0.980±0.015</td><td>0.9649±0.0044</td><td>0.9649±0.0042</td><td>0.9665±0.0038</td></tr><tr><td><a href="/facts/Hubble%2527s_constant/FJYfELCP">Hubble's constant</a> (km s−1 Mpc−1)</td><td> H 0 {\displaystyle H_{0}} </td><td>66.88±0.92</td><td>68.44±0.91</td><td>69.9±2.7</td><td>67.27±0.60</td><td>67.36±0.54</td><td>67.66±0.42</td></tr><tr><td><a href="/facts/Dark_energy/6bWIYewA">Dark energy</a> density</td><td> Ω Λ {\displaystyle \Omega _{\Lambda }} </td><td>0.679±0.013</td><td>0.699±0.012</td><td>0.711+0.033−0.026</td><td>0.6834±0.0084</td><td>0.6847±0.0073</td><td>0.6889±0.0056</td></tr><tr><td>Matter density</td><td> Ω m {\displaystyle \Omega _{m}} </td><td>0.321±0.013</td><td>0.301±0.012</td><td>0.289+0.026−0.033</td><td>0.3166±0.0084</td><td>0.3153±0.0073</td><td>0.3111±0.0056</td></tr><tr><td>Density fluctuations at 8h−1 Mpc</td><td>S8 = σ 8 {\displaystyle \sigma _{8}} ( Ω m {\displaystyle \Omega _{m}} /0.3)0.5</td><td>0.840±0.024</td><td>0.794±0.024</td><td>0.781+0.052−0.060</td><td>0.834±0.016</td><td>0.832±0.013</td><td>0.825±0.011</td></tr><tr><td><a href="/facts/Redshift/Qfl4VjDF">Redshift</a> of <a href="/facts/Reionization/tfqf1Ny9">reionization</a></td><td> z r e {\displaystyle z_{re}} </td><td>7.50±0.82</td><td>7.11+0.91−0.75</td><td>7.10+0.87−0.73</td><td>7.68±0.79</td><td>7.67±0.73</td><td>7.82±0.71</td></tr><tr><td><a href="/facts/Age_of_the_Universe/BaByputq">Age of the Universe</a> (Gy)</td><td> t 0 {\displaystyle t_{0}} </td><td>13.830±0.037</td><td>13.761±0.038</td><td>13.64+0.16−0.14</td><td>13.800±0.024</td><td>13.797±0.023</td><td>13.787±0.020</td></tr><tr><td>Redshift at <a href="/facts/Decoupling_(cosmology)/Kj6FbgLf">decoupling</a></td><td> z ∗ {\displaystyle z_{*}} </td><td>1090.30±0.41</td><td>1089.57±0.42</td><td>1087.8+1.6−1.7</td><td>1089.95±0.27</td><td>1089.92±0.25</td><td>1089.80±0.21</td></tr><tr><td>Comoving size of the sound horizon at z = z*(Mpc)</td><td> r ∗ {\displaystyle r_{*}} </td><td>144.46±0.48</td><td>144.95±0.48</td><td>144.29±0.64</td><td>144.39±0.30</td><td>144.43±0.26</td><td>144.57±0.22</td></tr><tr><td>100× angular scale of sound horizon at last-scattering</td><td> 100 θ ∗ {\displaystyle 100\,\theta _{*}} </td><td>1.04097±0.00046</td><td>1.04156±0.00049</td><td>1.04001±0.00086</td><td>1.04109±0.00030</td><td>1.04110±0.00031</td><td>1.04119±0.00029</td></tr><tr><td>Redshift with baryon-drag optical depth = 1</td><td> z d r a g {\displaystyle z_{drag}} </td><td>1059.39±0.46</td><td>1060.03±0.54</td><td>1063.2±2.4</td><td>1059.93±0.30</td><td>1059.94±0.30</td><td>1060.01±0.29</td></tr><tr><td>Comoving size of the sound horizon at z = zdrag</td><td> r d r a g {\displaystyle r_{drag}} </td><td>147.21±0.48</td><td>147.59±0.49</td><td>146.46±0.70</td><td>147.05±0.30</td><td>147.09±0.26</td><td>147.21±0.23</td></tr><tr><td>Legend</td><td colspan="7"><ul><li>68% limits: Parameter 68% <a href="/facts/Confidence_interval/NS8mG5UE">confidence limits</a> for the base <a href="/facts/Lambda-CDM_model/DmlhJHQU">ΛCDM model</a></li><li>TT, TE, EE: Planck <a href="/facts/Cosmic_microwave_background/ThB2HkLS">Cosmic microwave background</a> (CMB) <a href="/facts/Spectral_density/q3Rfs7b0">power spectra</a>; here TT represents temperature power spectrum, TE is temperature-polarization cross spectrum, and EE is polarisation power spectrum.</li><li>lowP: Planck <a href="/facts/Polarization_(waves)/fP33m0eD">polarization</a> data in the low-ℓ likelihood</li><li>lensing: CMB <a href="/facts/Gravitational_lens/LmxzvLs8">lensing</a> reconstruction</li><li>ext: External data (BAO+JLA+H0). BAO: <a href="/facts/Baryon_acoustic_oscillations/yVM31Wel">Baryon acoustic oscillations</a>, JLA: Joint <a href="/facts/Light_curve/zN0wdtaR">Light-curve</a> Analysis (of supernovae), H0: <a href="/facts/Hubble%2527s_law/FJYfELCP">Hubble constant</a></li></ul></td></tr></tbody></table>

<h2 id="see-also">See also</h2>
<ul>
<li>Physics portal</li><li>Spaceflight portal</li></ul>
<ul><li><a href="/facts/DustPedia/hJdDfhfR">DustPedia</a></li>
<li><a href="/facts/Lambda-CDM_model/DmlhJHQU">Lambda-CDM model</a></li>
<li><a href="/facts/List_of_cosmological_computation_software/l8CE7Xw2">List of cosmological computation software</a></li>
<li><a href="/facts/Observational_cosmology/032xpNtg">Observational cosmology</a></li>
<li><a href="/facts/Physical_cosmology/ww4ChbEq">Physical cosmology</a></li>
<li><a href="/facts/Terahertz_radiation/729QecPK">Terahertz radiation</a></li></ul>

<h2 id="further-reading">Further reading</h2>
<ul><li>Dambeck, Thorsten (May 2009). "Planck Readies to Dissect the Big Bang". <a href="/facts/Sky_%2526_Telescope/DSltKDCk">Sky & Telescope</a>. 117 (5): 24–28. <a href="/facts/Bibcode_(identifier)/9HtdQSGB">Bibcode</a>:<a href="https://ui.adsabs.harvard.edu/abs/2009S&T...117e..24D">2009S&T...117e..24D</a>. <a href="/facts/OCLC_(identifier)/Yqad8waq">OCLC</a> <a href="https://search.worldcat.org/oclc/318973848">318973848</a>.</li></ul>
<h2 id="external-links">External links</h2>

Wikimedia Commons has media related to Planck (spacecraft).

Wikinews has related news:
<ul><li>ESA launches Herschel Space Observatory and Planck Satellite</li></ul>

<ul><li>ESA
<ul><li><a href="http://www.esa.int/planck">Planck mission website</a></li>
<li><a href="http://sci.esa.int/planck/">Planck science website</a></li>
<li><a href="http://www.esa.int/Our_Activities/Operations/Planck">Planck operations website</a></li>
<li><a href="http://www.cosmos.esa.int/web/planck">Planck science results website</a></li></ul></li>
<li>NASA
<ul><li><a href="https://www.nasa.gov/planck/">Planck mission website</a></li>
<li><a href="http://irsa.ipac.caltech.edu/Missions/planck.html">NASA/IPAC Planck archive</a></li></ul></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">"Planck: The Scientific Programme" (PDF). European Space Agency. 2005. ESA-SCI(2005)1. Retrieved 6 March 2009. <a href="http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI%282005%291_V2.pdf" target="_blank">http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI%282005%291_V2.pdf</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">"Planck: The Scientific Programme" (PDF). European Space Agency. 2005. ESA-SCI(2005)1. Retrieved 6 March 2009. <a href="http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI%282005%291_V2.pdf" target="_blank">http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI%282005%291_V2.pdf</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Zu, H.; Dai, W.; de Waele, A.T.A.M. (2022). "Development of Dilution refrigerators – A review". Cryogenics. 121. doi:10.1016/j.cryogenics.2021.103390. ISSN 0011-2275. S2CID 244005391. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">"Coldest Known Object in Space Is Very Unnatural". Space.com. 7 July 2009. Retrieved 3 July 2013. <a href="http://www.space.com/6930-coldest-object-space-unnatural.html" target="_blank">http://www.space.com/6930-coldest-object-space-unnatural.html</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">"Planck: Mission Overview". NASA. Retrieved 26 September 2009. <a href="https://www.nasa.gov/mission_pages/planck/overview.html" target="_blank">https://www.nasa.gov/mission_pages/planck/overview.html</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">"Planck: The Scientific Programme" (PDF). European Space Agency. 2005. ESA-SCI(2005)1. Retrieved 6 March 2009. <a href="http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI%282005%291_V2.pdf" target="_blank">http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI%282005%291_V2.pdf</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">"The Planck High Frequency Instrument (HFI)". Jet Propulsion Laboratory. 21 March 2013. Archived from the original on 25 April 2015. Retrieved 22 March 2013. <a href="https://web.archive.org/web/20150425082904/http://planck.caltech.edu/hfi.html" target="_blank">https://web.archive.org/web/20150425082904/http://planck.caltech.edu/hfi.html</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
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<li id="fn:34">See Table 9 in Planck Collaboration (2013). "Planck 2013 results. I. Overview of products and scientific results". Astronomy & Astrophysics. 571: A1. arXiv:1303.5062. Bibcode:2014A&A...571A...1P. doi:10.1051/0004-6361/201321529. S2CID 218716838. <a href="/wiki/ArXiv_(identifier)" target="_blank">/wiki/ArXiv_(identifier)</a> <a href="#fnref:34" class="footnote-back-ref">↩</a></li>
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<li id="fn:36">Planck Collaboration (2013). "Planck 2013 results. XVI. Cosmological parameters". Astronomy & Astrophysics. 571: A16. arXiv:1303.5076. Bibcode:2014A&A...571A..16P. doi:10.1051/0004-6361/201321591. S2CID 118349591. <a href="/wiki/ArXiv_(identifier)" target="_blank">/wiki/ArXiv_(identifier)</a> <a href="#fnref:36" class="footnote-back-ref">↩</a></li>
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<li id="fn:38">See Table 9 in Planck Collaboration (2013). "Planck 2013 results. I. Overview of products and scientific results". Astronomy & Astrophysics. 571: A1. arXiv:1303.5062. Bibcode:2014A&A...571A...1P. doi:10.1051/0004-6361/201321529. S2CID 218716838. <a href="/wiki/ArXiv_(identifier)" target="_blank">/wiki/ArXiv_(identifier)</a> <a href="#fnref:38" class="footnote-back-ref">↩</a></li>
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<li id="fn:42">See Table 9 in Planck Collaboration (2013). "Planck 2013 results. I. Overview of products and scientific results". Astronomy & Astrophysics. 571: A1. arXiv:1303.5062. Bibcode:2014A&A...571A...1P. doi:10.1051/0004-6361/201321529. S2CID 218716838. <a href="/wiki/ArXiv_(identifier)" target="_blank">/wiki/ArXiv_(identifier)</a> <a href="#fnref:42" class="footnote-back-ref">↩</a></li>
<li id="fn:43">Planck Collaboration (2013). "Planck 2013 results. XVI. Cosmological parameters". Astronomy & Astrophysics. 571: A16. arXiv:1303.5076. Bibcode:2014A&A...571A..16P. doi:10.1051/0004-6361/201321591. S2CID 118349591. <a href="/wiki/ArXiv_(identifier)" target="_blank">/wiki/ArXiv_(identifier)</a> <a href="#fnref:43" class="footnote-back-ref">↩</a></li>
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<li id="fn:49">Planck Collaboration (2016). "Planck 2015 results. XIII. Cosmological parameters". Astronomy & Astrophysics. 594: A13. arXiv:1502.01589. Bibcode:2016A&A...594A..13P. doi:10.1051/0004-6361/201525830. S2CID 119262962. <a href="/wiki/ArXiv_(identifier)" target="_blank">/wiki/ArXiv_(identifier)</a> <a href="#fnref:49" class="footnote-back-ref">↩</a></li>
<li id="fn:50">Planck Collaboration (2020). "Planck 2018 results. VI. Cosmological parameters (See PDF, page 15, Table 2)". Astronomy & Astrophysics. 641: A6. arXiv:1807.06209. Bibcode:2020A&A...641A...6P. doi:10.1051/0004-6361/201833910. S2CID 119335614. <a href="/wiki/ArXiv_(identifier)" target="_blank">/wiki/ArXiv_(identifier)</a> <a href="#fnref:50" class="footnote-back-ref">↩</a></li>
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</ol>

Planck (spacecraft) open-in-new

Planck (spacecraft)