MESSENGER Spacecraft Crashing on Mercury

We are in the golden age of robotic exploration of the Solar System. Almost all the planets have a spacecraft studying them or on the way. It is amazing what these human engineered and built robots can do. 

Click to enlarge. All of the robots currently exploring the Solar System! Image Credit: Olaf Frohn and the Planetary Society

The MESSENGER spacecraft has been studying Mercury since 2011. It has completely mapped Mercury twice, discovering past volcanic activity and other interesting features, such as frozen water at its permanently shadowed north pole. This was unexpected, since the temperature on most of Mercury's surface fluctuates between -270 degrees Fahrenheit and 800 degrees Fahrenheit. You can check out a highly detailed zoomable map here. 

Image Credit: NASA

By the way, it was an adventure just getting MESSENGER to Mercury. Because Mercury is so close to the Sun, if the spacecraft had gone straight there, it would have been captured by the Sun's gravity before it could slow down enough to fall into orbit around Mercury. It would have burned up! NASA had to send the spacecraft on a long, looping journey, flying by Earth, Venus, and passing by Mercury 3 times before it could call into orbit. 

MESSENGER's loopy trajectory. Image Credit: NASA and Wikipedia Commons

MESSENGER's mission has been extended twice. Its primary mission ended in March of 2012, but engineers have done a great job extending the life of the spacecraft, so it carried on its work. However, MESSENGER does have limited fuel, and now it is literally running on fumes, maintaining its altitude by venting helium gas out of its thrusters. As MESSENGER has been getting closer and closer to the surface of Mercury, it has been able to take some beautifully detailed images. This week, on April 30th, MESSENGER is expected to totally run out of fuel, and crash into the surface of Mercury. It will be moving at about 8,750 miles per hour, and could create a crater as wide as 52 feet across!

Gullies in the rim of a volcanic vent. Image Credit: NASA / JHUAPL / CIW

The highest resolution image yet captured of Mercury, 1.1 meters per pixel. This image was taken on April 24, days before MESSENGER will crash into the surface. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

19.9 meters/pixel. Featured here is the ejecta blanket of a fresh impact crater located just outside the scene. Ejecta scoured the surface leaving behind beautiful patterns of secondary craters. Image Credit:
NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Global mosaic of Mercury captured by MESSENGER. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

MESSENGER will be hidden from Earth when it impacts, but scientists will know the mission is ended when they are unable to establish radio contact with the spacecraft. I am impressed the scientists were able to keep MESSENGER running as long as they did, and grateful we have had such a successful mission at Mercury. 

The European Space Agency and the Japanese Space Agency are working together to send another mission to Mercury. BepiColombo is scheduled to launch in 2017. 

As always, you can learn more about space and science by visiting the Dome Planetarium at the Peoria Riverfront Museum. And if you are like the combination of spacy visuals and ambient music, don't miss Space Out! on May 1.