The European Space Agency's (ESA)Rosetta robotic spacecraft has sent back images showing its target comet finally developing a coma. The 67P/Churyumov-Gerasimenko's trail of dust is growing longer and longer at it comes closer to the Sun.
The images of 67P/Churyumov-Gerasimenko sent back by the Rosetta were taken during a period of time between March 27 and May 4. The Rosetta spacecraft was launched back in 2004 in an effort to conduct a detailed study of its target comet. 10 years after it was launched onboard an Ariane 5 rocket, the spacecraft is now closing in on its goal. As the Rosetta closed the distance between itself and its target comet, the images being sent back by the spacecraft are getting clearer and clearer.
"It's beginning to look like a real comet," said OSIRIS principal investigator Holger Sierks."It's hard to believe that only a few months from now, Rosetta will be deep inside this cloud of dust and en route to the origin of the comet's activity." . OSIRIS stands for Optical, Spectroscopic and Infrared Remote Imaging System.
When the first image of the sequence was taken, the Rosetta was still over 3.1 million miles (5 million kilometers) away from the comet. By May 4 however, the spacecraft and the comet covered even more distance and the "hunter" and "prey" are now a mere 1.2 million miles (2 million kilometers) away from each other. While that sounds like a very large distance in Earth terms, 1,2 million miles is only a stone's throw away in astronomical terms.
As comets travel through their orbits, they gradually move closer to the Sun. This causes the development of a visible trail of dust and debris known as a coma. 67P/Churyumov-Gerasimenko has an orbit that lasts about 6.5 years. To date, the comet is around 600 million km away from the Sun. However, this distance is enough to warm up the surface of the comet. This causes the comet's icy shell to sublimate. Moreover, gas from the comet's core also forces its way out to the surface further contributing to 67P/Churyumov-Gerasimenko wispy trail. The comet's coma is now around 800 miles long.
"These early observations are helping us to develop models of the comet that will be essential to help us navigate around it once we get closer," said the ESA's Rosetta spacecraft operations manager Sylvain Lodiot.
As the comet continues to travel closer to the Sun along its orbit, scientists expect that its coma will lengthen even more as activity on the comet continues to rise. The comet is expected to reach its closest position relative to the Sun by August next year. Soon afterwards, it will continue on its way to the outer reaches of the Solar System.
