Two New Orbiters Get Right to Work
When the going gets tough, the tough do science! No doubt about it, getting to Mars is a challenge, and once you get there, the rewards are great. So it is this week with two spacecraft who took up residence in Mars orbit.
Within days of their arrival at Mars the NASA MAVEN spacecraft and the Indian Space Research Organization’s MOM/Mangalyaan orbiter returned their first data and images of the Red Planet. MAVEN was sent to Mars s0lely to study the atmosphere, and its first data show the planet from the spacecraft’s viewpoint of 36,500 km (58,765 miles) above the surface. Its ultraviolet-sensitive imaging spectrograph (an instrument) studied the fine changes in UV light as it passed through the upper atmosphere. It showed ultraviolet light from the Sun scattered by atomic hydrogen gas, which lies in an extended cloud that goes to thousands of kilometers above the planet’s surface. The blue (leftmost) part of this image shows how extensive that cloud is. The green image (middle left) is a different wavelength of UV light that is primarily sunlight reflected off of atomic oxygen. Mars’ gravity is holding the oxygen closer to the surface. Red (middle right) shows ultraviolet sunlight reflected from the planet’s surface. The final panel is a composite map of the other views. The bright spot in the lower right is light reflected either from polar ice or clouds.
These gases are a result of water and carbon dioxide breaking down in the atmosphere. The trick for MAVEN now is to chart the escape of hydrogen and oxygen from the planet over time. Its nominal mission is one year, and should give scientists a much better understanding of how much water has escaped from the Martian atmosphere over longer periods of time.
MOM Gets Her First Images of Mars
The MOM Mangalyaan mission is busily snapping and sending back images of the Red Planet from its orbit roughly 7,000 km (4,300 miles) above the surface. As you can see, it’s traveling in a closer orbit so as to allow the mission to study the surface more closely. MAVEN is is in a longer higher orbit that will (at first) allow it to study most (if not all) of the planet’s atmosphere.
As MAVEN is doing, the MOM is performing early science observations (sometimes called “commissioning” science) to calibrate and test the instruments after their long voyage from Earth. MOM is a multi-purpose mission, combining imaging with other science to get a complete view of Mars and its atmosphere.
The results are exciting, and are proving that the MOM approach (which is a science “proof of concept” mission) is working. The camera’s images give an immediate positive feedback. Not only will it be used to track changes in surface features, but it can show (as it does here) the thin atmosphere of Mars. Further along in the mission, the spacecraft’s controllers hope to capture images of Mars’s two moons: Phobos and Deimos. Fairly soon we should hear about data from the other instruments aboard MOM: the thermal infrared system (which helps take the temperature of the planet), the methane sensor (looking for methane emissions from the surface), the Lyman-alpha photometer (which specifically looks for deuterium and hydrogen in the atmosphere), and the Mars Exospheric Neutral Composition analyzer, which is another instrument used to study the components of the atmosphere. There’s more to come from these two missions, so stay tuned!
