[meteorite-list] NASA's MAVEN Studies Passing Comet and Its Effects

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.php?feature=4345

NASA's MAVEN Studies Passing Comet and Its Effects
Jet Propulsion Labotary
October 19, 2014

MAVEN Mission Status Report

NASA's newest orbiter at Mars, MAVEN, took precautions to avoid harm from 
a dust-spewing comet that flew near Mars today and is studying the flyby's 
effects on the Red Planet's atmosphere.

The MAVEN spacecraft -- full name Mars Atmosphere and Volatile Evolution 
-- reported back to Earth in good health after about three hours of precautions 
against a possible collision with high-velocity dust particles released 
by comet C/2013 A1 Siding Spring.

"We're glad the spacecraft came through, we're excited to complete our 
observations of how the comet affects Mars, and we're eager to get to 
our primary science phase," said MAVEN Principal Investigator Bruce Jakosky 
of the University of Colorado, Boulder.

MAVEN began orbiting Mars on Sept. 21. The opportunity to study this rare 
near-miss of a planet by a comet comes during the project's commissioning 
phase. A few weeks of instrument calibration and orbit fine-tuning remain 
before the start of the primary science phase. The mission will study 
the upper atmosphere of Mars and its interaction with the solar wind.

Comet Siding Spring hurtled past Mars today at about 125,000 mph (56 kilometers 
per second), coming within about 87,000 miles (139,500 kilometers) of 
the planet. That is equivalent to about one-third of the distance between 
Earth and Earth's moon. The closest approach by the comet's nucleus came 
at about 11:27 a.m. PDT (2:27 p.m. EDT). The period when dust from the 
comet was most likely to reach Mars and the orbits of spacecraft around 
Mars peaked about 100 minutes later.

>From about 10:45 a.m. to 2 p.m. PDT (1:45 p.m. to 5:00 p.m. EDT) MAVEN 
kept in a defensive posture to reduce its profile relative to the direction 
from which the comet's high-velocity dust particles would come. In that 
"hunkered down" orientation, its main antenna was not facing the right 
way for transmitting to Earth, so communications were maintained at low 
data rate via a secondary antenna. Also, the mission performed a maneuver 
on Oct. 2 that set its orbit timing so that the spacecraft was behind 
Mars, relative to the possible dust flow, from about 12:53 p.m. to 1:23 
p.m. PDT (3:53 p.m. to 4:23 p.m. EDT).

Downlink of data has begun from MAVEN observations of the comet and Mars' 
atmosphere. Some observations are designed to provide information about 
the composition of the gases and dust being released by the comet. Others 
are investigating possible interaction between material from the comet 
and the atmosphere of Mars.

Three NASA Mars orbiters, two Mars rovers and other assets on Earth and 
in space are studying comet Siding Spring. This comet is making its first 
visit this close to the sun from the outer solar system's Oort Cloud, 
so the concerted campaign of observations may yield fresh clues to our 
solar system's earliest days more than 4 billion years ago.

MAVEN's principal investigator is based at the University of Colorado's 
Laboratory for Atmospheric and Space Physics. The university provided 
two science instruments and leads science operations, as well as education 
and public outreach, for the mission. NASA's Goddard Space Flight Center 
in Greenbelt, Maryland, manages the MAVEN project and provided two science 
instruments for the mission. Lockheed Martin built the spacecraft and 
is responsible for mission operations. The University of California at 
Berkeley's Space Sciences Laboratory also provided four science instruments 
for the mission. NASA's Jet Propulsion Laboratory in Pasadena, California, 
provides navigation and Deep Space Network support, as well as the Electra 
telecommunications relay hardware and operations.

For more about MAVEN, visit:

http://www.nasa.gov/maven

Media Contact
Nancy Jones / Bill Steigerwald
Goddard Space Flight Center, Greenbelt, Maryland
301-286-0039 / 301-286-5017
nancy.n.jones at nasa.gov / william.a.steigerwald at nasa.gov

Dwayne Brown
NASA Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

Guy Webster
Jet Propulsion Laboratory, Pasadena, California
818-354-6278
guy.webster at jpl.nasa.gov