Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Planetesimal
open-in-new
<p>Planetesimals are solid objects thought to exist in <a href="/facts/Protoplanetary_disk/FtfSbP61">protoplanetary disks</a> and <a href="/facts/Debris_disk/ClIxTnge">debris disks</a>. Believed to have formed in the <a href="/facts/Solar_System/QIcLSazQ">Solar System</a> about 4.6 billion years ago, they aid study of <a href="/facts/Formation_and_evolution_of_the_Solar_System/cgElXHpM">its formation</a>. </p>