MESSENGER sends us farewell pictures from Mercury ahead of explosive demise

28 Apr 2015

Mercury, via NASA's MESSENGER programme

NASA’s MESSENGER spacecraft is about to spiral towards its explosive death, but before it does it has sent us some incredible holiday snaps from Mercury.

Responsible for pretty much all of our real knowledge of the planet nearest the sun, MESSENGER has been circling Mercury for years taking photos of its surface.

However, with fuel running low, the doomed spacecraft is preparing itself for its final trip down, all the way down, to its death.

Standing for ‘Mercury Surface, Space Environment, Geochemistry, and Ranging’ spacecraft, MESSENGER will unfortunately crash on the far side of the planet, so scientists won’t get to see it’s great finale – which is expected on Thursday at some stage.

Today it underwent its final manoeuvre, which gave MESSENGER a couple more days of life.

“Following this last manoeuvre, we will finally declare the spacecraft out of propellant, as this manoeuvre will deplete nearly all of our remaining helium gas,” said Daniel O’Shaughnessy, mission systems engineer at the Johns Hopkins University Applied Physics Laboratory.

“At that point, the spacecraft will no longer be capable of fighting the downward push of the sun’s gravity.”

It took six-and-a-half years to get to Mercury, arriving in March 2011. However, MESSENGER was such a good little worker that its one-year project was extended several times, which is a lesson to us all.

One key science finding in 2012 provided compelling support for the hypothesis that Mercury harbours abundant frozen water and other volatile materials in its permanently shadowed polar craters.

Another, better, finding was all these pictures.

MESSENGER‘s composite tie-dye Mercury

The four faces of Mercury

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

This tie-dye of Mercury’s surface is thanks to the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) instrument aboard that studies both the exosphere and surface of the planet.

To learn more about the minerals and surface processes on Mercury, the Visual and Infrared Spectrometer (VIRS) portion of MASCS has been diligently collecting single tracks of spectral surface measurements since 2011. The track coverage is now extensive enough that the spectral properties of both broad terrains and small, distinct features such as pyroclastic vents and fresh craters can be studied.

MESSENGER, behind the scenes

Wavelengths of light from surface of Mercury

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

MASCS collects hundreds of different wavelengths of light, which lets it “probe the mineralogy” of the surface of Mercury. These are portrayed in wavelengths that the human eye can see, so red, green and blue.

The ‘fireworks’ result from a combination of physical and chemical differences on the surface, including mineralogical diversity and the exposure age of the craters.

MESSENGER catches Mercury feeling blue

Mercury with blue surface

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

This colourful view of Mercury was produced by using images from the color base map imaging campaign during MESSENGER‘s primary mission. These colours are not what Mercury would look like to the human eye, but rather the colours enhance the chemical, mineralogical and physical differences between the rocks that make up Mercury’s surface.

Lastly, MESSENGER spots a brilliant solar flare

Bright solar flare

Credit: NASA/STEREO/Helioviewer

A solar flare erupted on the far side of the sun on June 4, 2011, and sent solar neutrons out into space. Solar neutrons don’t make it to all the way to Earth, but NASA’s MESSENGER, orbiting Mercury, found strong evidence for the neutrons, offering a new technique to study these giant explosions.

Gordon Hunt was a journalist with Silicon Republic