{"id":16925,"date":"2014-10-09T17:25:59","date_gmt":"2014-10-09T09:25:59","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/fleet-of-mars-probes-set-to-observe-comet-flyby\/"},"modified":"2014-10-09T17:25:59","modified_gmt":"2014-10-09T09:25:59","slug":"fleet-of-mars-probes-set-to-observe-comet-flyby","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/fleet-of-mars-probes-set-to-observe-comet-flyby\/","title":{"rendered":"Fleet of Mars probes set to observe comet flyby"},"content":{"rendered":"

STORY WRITTEN FOR CBS NEWS \u201cSPACE PLACE\u201d & USED WITH PERMISSION<\/p>\n

\"An
An artist\u2019s concept of Comet Siding Spring (2013 A1) and Mars. Closest approach to Mars is on Oct. 19, 2014. Credit: NASA<\/figcaption><\/figure>\n

An international fleet of five Mars orbiters and two rovers will have ringside seats when a mountain-size comet streaks by on Oct. 19, passing within a scant 87,000 miles of the red planet at a blistering 126,000 mph, NASA scientists said Thursday.<\/p>\n

While 87,000 miles might seem like a comfortable margin, it\u2019s a near miss in astronomical terms, giving excited scientists a rare opportunity to study a comet from the remote Oort Cloud, a vast swarm of icy debris left over from the birth of the solar system 4.6 billion years ago.<\/p>\n

\u201cThis comet apparition is so close to Mars that if we put it in our own system, it\u2019s coming one third of the distance between the Earth and the moon,\u201d said Carey Lisse, an astrophysicist at Johns Hopkins University Applied Physics Laboratory. \u201cIt\u2019s tail would extend from between the Earth to the moon and its coma would fill about half the distance from the Earth to the moon. It\u2019s that kind of size object.\u201d<\/p>\n

Comet Siding Spring, named after the Australian observatory where it was discovered in January 2013, will make its closest approach to Mars at 2:27 p.m. EDT Oct. 19. The comet should be visible to Earth-bound observers in the southern hemisphere using binoculars or telescopes.<\/p>\n

But the Mars spacecraft will have the best seats in the house.<\/p>\n

\u201cWe\u2019re going to observe an event that happens maybe once every million years,\u201d Jim Green, director of NASA\u2019s planetary science division, told reporters. \u201cAnd this is where a comet coming from the farthest reaches of the sun\u2019s gravity will come to the inner part of our solar system. This comet will fly right in front of the planet Mars. Mars will be blanketed in cometary material.\u201d<\/p>\n

NASA\u2019s Mars Reconnaissance Orbiter will use its high-resolution camera to photograph the comet\u2019s nucleus, to map its shape and rotation, its brightness or lack thereof, the composition of its coma \u2014 the tenuous cloud of material around the nucleus that has been boiled away by the sun \u2014 and to look for any changes in the martian atmosphere caused by the comet\u2019s passage.<\/p>\n

The Mars Odyssey orbiter will study the comet\u2019s coma and tail in infrared and visible light while NASA\u2019s newly arrived Maven orbiter, designed to study the upper atmosphere of Mars, will make ultraviolet observations and provide even more detail about Siding Spring\u2019s possible interaction with the martian atmosphere.<\/p>\n

\"Mars-orbiters-comet-siding-spring-close-call-br2\"
This artist\u2019s concept shows the NASA Mars orbiters lining up behind Mars for their \u201cduck and cover\u201d maneuver to shield them from comet dust that may result from the close flyby of Comet Siding Spring (C\/2013 A1) on Oct. 19, 2014. Credit: NASA\/JPL-Caltech<\/figcaption><\/figure>\n

NASA\u2019s Curiosity and Opportunity rovers on the surface also will get in on the action, attempting to photograph the comet as it moves across the red planet\u2019s sky. The cameras were not designed to image objects as faint as a comet, but engineers are hopeful.<\/p>\n

The European Space Agency\u2019s Mars Express satellite also will make observations and India\u2019s newly arrived Mars Orbiter Mission, or MOM, spacecraft will attempt observations with its main color camera. In a recent Twitter posting, the MOM project said it was \u201cjoining the welcome party for comet #SidingSpring. @MarsCuriosity, @MAVEN2Mars, @HiRISE, #MarsOdyssey & #MarsExpress are there too. Excited!\u201d<\/p>\n

Earth-based telescopes and a variety of other spacecraft also will be trained on Mars during the encounter, including the Hubble Space Telescope, along with amateur astronomers around the world.<\/p>\n

\u201cWe\u2019re getting ready for a spectacular set of observations,\u201d Green said.<\/p>\n

Siding Spring, known more formally as C\/2013 A1, is approaching Mars from below the plane of the planets. Because it is moving in a retrograde direction, that is, opposed to the movement of the planets in their orbits, its velocity relative to Mars will be a very high 35 miles per second. At that speed, even dust grains post a serious threat to spacecraft in orbit around Mars.<\/p>\n

\u201cSo anything that comes off the comet that hits Mars or a spacecraft is going to pack a large amount of kinetic energy, a real wallop,\u201d Lisse said. \u201cThat\u2019s one of the things we\u2019ve been really worried about.\u201d<\/p>\n