The Rosetta spacecraft, which arrived at comet 67P/Chuyurmov-Gerasimenko on 6 August, found that body to be warmer than expected.
The Visible, Infrared and Thermal Imaging Spectrometer (VIRTIS) measured the surface temperature of the comet, a remarkable 94 degrees below zero Fahrenheit. This instrument is designed to study how temperatures change on various parts of the body as comets approach the Sun.
Rosetta took images of the comet from just 145 miles away from the body as the spacecraft approached. This is significantly warmer than the astronomers had predicted from the icy objects. These measurements were recorded in the middle of July, when the vehicle was between 8,699 and 3.106 miles from the comet.
"Our first clear views of the comet have given us plenty to think about. Is this double-lobed structure built from two separate comets that came together in the Solar System's history, or is it one comet that has eroded dramatically and asymmetrically over time? Rosetta, by design, is in the best place to study one of these unique objects," Matt Taylor, Rosetta project scientist for the European Space Agency (ESA), said.
The Philae lander will be deployed to the surface of the comet in November 2014. There, it will study the chemical makeup of a comet surface directly for the first time in history, and return the first images ever taken from one of the frozen bodies.
Mission planners on the Rosetta system are currently surveying the frozen object, searching for an ideal landing spot for Philae. At least five potential landing spots will be identified for the vehicle by the end of August, before a final decision is made in the middle of September. Using VIRTIS, researchers are examining the first few inches of the surface, measuring density, internal structure and thermal properties.
"Over the next few months, in addition to characterizing the comet nucleus and setting the bar for the rest of the mission, we will begin final preparations for another space history first: landing on a comet," Taylor told the press.
Rosetta possess 11 science instruments, including VIRTIS, to study the frozen surface. Philae is equipped with ten additional pieces of equipment for use on the frozen surface.
The smaller craft was named after Philae Island in the Nile, where archaeologists discovered an obelisk that was used, along with the Rosetta Stone, to help decipher Egyptian hieroglyphs for the first time.
Rosetta will continue to monitor the comet as the dirty snowball whips around the Sun on 13 August 2015 and beyond.
