Archer's Comet was a comet discovered by Enterprise NX-01 in 2151. With a diameter of 82.6 kilometers, the comet was the largest ever observed by Humans or Vulcans. It was named after Captain Jonathan Archer, following confirmation that it was not listed in the Vulcan database.
Initially disregarded as merely "rock and ice" by Sub-Commander T'Pol, upon further analysis it was discovered to contain large quantities of eisillium located under a twenty-meter thick layer of magnesite. Since eisilium was extremely rare, Captain Jonathan Archer suggested obtaining a sample with the transporter. With the layer located out of transporter range, Lieutenant Malcolm Reed suggested making use of the portable drilling rig with Ensign Travis Mayweather's assistance.
During the "comet walk," the drilling team experienced several setbacks, including a broken drill bit due to a layer of magnesite, a rotational axis shift resulting in the dawn approaching sooner than expected causing the temperature to increase by several hundred degrees, and the Shuttlepod 1 falling into a chasm due to melting ice. Enterprise attempted to use the grappler and pull the shuttlepod to safety. However, a secure hold could not be obtained. The drilling team was eventually rescued by the Vulcan starship Ti'Mur under command of Captain Vanik. (ENT: "Breaking the Ice")
Scans of the comet were reported by Enterprise to Starfleet Command, where Admiral Maxwell Forrest found them "incredible." He later relayed this enthusiasm to Archer. (ENT: "Fortunate Son")