Bangalore: Over the next few days, a rare celestial phenomenon will offer a treat to star-gazers. A comet that has managed to get the closest to an Inner Planet (Mercury, Venus, Earth, Mars) in recorded history will be visible via telescopes when it will be near Mars for a few days after October 17.
Jawaharlal Nehru Planetarium has planned to allow visitors in the evenings to avail the opportunity to view the comet, named Siding Spring, which will be 10 times closer to Earth than any other comet known so far.
BS Shailaja, director, Jawaharlal Nehru Planetarium, told Bangalore Mirror, the comet would be visible using a telescope in the evenings. “Those interested and equipped with a telescope can point it towards Mars and observe the comet which will appear as a faint dot. The advantage is that the comet will be visible in the field of view of Mars and people don’t have to hunt for it,” she said, adding that the best time would be the evening of October 19 when the comet would be closest to Mars in the high western sky hemisphere. Experts said those equipped with telescopes of 8-inch (20-cm) or more can follow the comet during its encounter with Mars.
The closest distance between Mars and Comet Siding Spring will be 1,39,200 km – less than half the distance between Earth and Moon – around midnight of October 19.
The passing comet is being received by space scientists with a mixture of excitement and concern. Excitement, because of the vast opportunities the comet offers to study it using the presently orbiting missions around Mars; and concern, because of the possibilities that fragments in the comets tail damaging or destroying the orbiting spacecraft.
One of the orbiting spacecraft is India’s Mars Orbiter Mission (MOM) which entered the orbit around Mars on the morning of September 24. However, both Indian Space research Organisation and US’ National Aeronautics and Space Administration (NASA) (whose Mars Atmosphere and Volatile Evolution – or MAVEN – entered the Martin orbit a day before MOM’s) have taken evasive actions. They have altered the orbits of the space craft to ensure that they are on the other side of the red plant when the comet passes at its closest point to Mars to avoid possible fragments from the comet’s tail.
According to Kiran Kumar, director, ISRO’s Space Application Centre, MOM’s orbit alteration to avoid the comet’s fragments consumed about 1.9 Kg of fuel. As a result of the orbit alteration, MOM will be at an altitude of 400 km from the Martian surface on the other side of the red planet as compared to the comet. The minimum distance between MOM and the comet is expected to be about 1,40,000 kms, but with Mars in between. John Grunsfeld, associate administrator for NASA’s science mission directorate, is already on record while explaining the importance of studying Comet Siding spring. He said studying Comet Siding Spring could provide clues to the solar system’s origins. The comet is known to have come from the Oort cloud at a distance of between 5,000 and 10,000 Astronomical Units (AU) (one AU equals 150 million km).
Just the facts
Comet was discovered on January 3, 2013, by astronomer Robert McNaught at Siding Spring Observatory in Australia
It was designated the name C/2013 A1
This is the first comet to enter the innet planet circle of the solar system in recorded history
The comet comes from the Oort cloud, which surrounds the solar system at a distance of between 5,000 AU and 10,000 AU
It will be the closest from Mars at a distance of 1,39200 kms on October 19
It can be viewed using a telescope of more than 20 cms
In orbit around Mars are the spacecrafts Mars Reconnaissance Orbiter, 2001 Mars Odyssey, MAVEN (All three are NASA’s), Mars Express of European Space Agency, and India’s MOM