mercury messenger crash rachel crane orig_00001501.jpg
mercury messenger crash rachel crane orig_00001501.jpg
Now playing
01:40
Space probe doomed to crash into planet
NASA releases first ever ISS video shot at 8K
NASA
NASA releases first ever ISS video shot at 8K
Now playing
01:16
NASA shoots first 8K video of Earth
NASA
Now playing
00:59
Why did NASA launch 450,000 gallons of water?
In this photo released by NASA, the Northrop Grumman Antares rocket, with Cygnus resupply spacecraft onboard, launches from Pad-0A, Saturday, Nov. 17, 2018 at NASA's Wallops Flight Facility in Va. (Joel Kowsky/NASA via AP)
Joel Kowsky/NASA/AP
In this photo released by NASA, the Northrop Grumman Antares rocket, with Cygnus resupply spacecraft onboard, launches from Pad-0A, Saturday, Nov. 17, 2018 at NASA's Wallops Flight Facility in Va. (Joel Kowsky/NASA via AP)
Now playing
00:34
Watch NASA launch cargo ship into space
SANTA BARBARA, CA - OCTOBER 07: The SpaceX Falcon 9 rocket (R) separates from the space craft (L) behind the rocket trail after launching from Vandenberg Air Force Base carrying the SAOCOM 1A and ITASAT 1 satellites, as seen on October 7, 2018 near Santa Barbara, California. After launching the satellites, the Falcon 9 rocket successfully returned to land on solid ground near the launch site rather than at sea. The satellites will become part of a six-satellite constellation that will work in tandem with an Italian constellation known as COSMO-SkyMed.    (Photo by David McNew/Getty Images)
David McNew/Getty Images
SANTA BARBARA, CA - OCTOBER 07: The SpaceX Falcon 9 rocket (R) separates from the space craft (L) behind the rocket trail after launching from Vandenberg Air Force Base carrying the SAOCOM 1A and ITASAT 1 satellites, as seen on October 7, 2018 near Santa Barbara, California. After launching the satellites, the Falcon 9 rocket successfully returned to land on solid ground near the launch site rather than at sea. The satellites will become part of a six-satellite constellation that will work in tandem with an Italian constellation known as COSMO-SkyMed. (Photo by David McNew/Getty Images)
Now playing
01:09
SpaceX rocket launch lights up evening sky
JAXA astroid ryugu images
Twitter / @haya2e_jaxa
JAXA astroid ryugu images
Now playing
00:33
Robot sends new images from asteroid's surface
Massive structure on Saturn
NASA
Massive structure on Saturn
Now playing
01:05
New vortex discovered above Saturn
The SpaceX launch of a Falcon 9 rocket marks another milestone for Kennedy Space Center's Launch Complex 39-A.
NASA
The SpaceX launch of a Falcon 9 rocket marks another milestone for Kennedy Space Center's Launch Complex 39-A.
Now playing
02:00
60 years of NASA's history in 120 seconds
NASA TV
Now playing
01:39
Watch NASA launch probe that will explore sun
nasa lagoon nebula new images lon orig_00000000.jpg
NASA
nasa lagoon nebula new images lon orig_00000000.jpg
Now playing
01:19
Stunning virtual tour of the Lagoon Nebula
Artist's concept of the Solar Probe Plus spacecraft approaching the sun. In order to unlock the mysteries of the corona, but also to protect a society that is increasingly dependent on technology from the threats of space weather, we will send Solar Probe Plus to touch the sun.
Johns Hopkins University Applied Physics Laboratory/NASA
Artist's concept of the Solar Probe Plus spacecraft approaching the sun. In order to unlock the mysteries of the corona, but also to protect a society that is increasingly dependent on technology from the threats of space weather, we will send Solar Probe Plus to touch the sun.
Now playing
00:59
Listen: The sun is not silent
NASA's Goddard Space Flight Center/David Ladd
Now playing
01:26
Breathtaking virtual tour of the Moon in 4K
This composite image, derived from data collected by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA's Juno mission to Jupiter, shows the central cyclone at the planet's north pole and the eight cyclones that encircle it.
NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM
This composite image, derived from data collected by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA's Juno mission to Jupiter, shows the central cyclone at the planet's north pole and the eight cyclones that encircle it.
Now playing
01:02
NASA mission discovers Jupiter's inner secrets
N.R.Fuller, National Science Foundation
Now playing
00:46
'Fingerprint' of earliest light in universe detected
Now playing
00:46
'Super blue blood moon' lights up the skies
what is a black moon orig jpm_00000000.jpg
NASA
what is a black moon orig jpm_00000000.jpg
Now playing
01:04
What's in a moon's name?

Story highlights

Spacecraft to crash on Mercury this month

MESSENGER probe has been in orbit since 2011

CNN —  

Let’s start with a pop quiz (space junkies can skip this test). True or False, Mercury is:

1) The planet closest to the sun in our solar system

2) So hot that water couldn’t possibly exist there

3) Something used in old-style glass thermometers

4) A planet you don’t think about very often

Answers: True, False, True (but not what we’re talking about in this story) and I’m guessing No. 4 is true too.

If you flunked the test, it might be because Mercury (the planet) suffers from bad (or very little) press.

Or, maybe it’s just bad lighting.

Mercury orbits about 35,983,125 miles from the sun. Compare that to Earth – we’re about 93 million miles from the sun. Mercury’s closeness to the sun makes it hard to see except at dawn and twilight. This may be one reason we don’t think about it much.

Venus, on the other hand, the planet between Earth and Mercury, appears to be the brightest planet in the sky. It’s so bright it’s been mistaken for an airplane.

Pilot sends plane into dive after mistaking Venus for oncoming plane

But back to Mercury.

It’s getting some attention from the media now because it’s about to get a visitor.

The NASA spacecraft MESSENGER (an acronym for MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is about to crash onto Mercury.

The probe was launched in 2004 and traveled more than six and a half years before it started orbiting Mercury on March 18, 2011. Now, MESSENGER is running out of fuel and NASA says it will hit the planet’s surface at 8,750 mph (3.91 kilometers per second) around April 30.

You won’t be able to see it hit because Messenger will crash on the side of Mercury facing away from Earth.

There’s no way to save the spacecraft, but mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, have been doing what they can to delay the inevitable. They’ve been using the little bit of fuel left on board to maneuver the spacecraft to keep it in orbit. They’ll do one final maneuver on Friday, April 24.

“Following this last maneuver, we will finally declare the spacecraft out of propellant, as this maneuver will deplete nearly all of our remaining helium gas,” mission systems engineer Daniel O’Shaughnessy said at a recent media briefing. “At that point, the spacecraft will no longer be capable of fighting the downward push of the sun’s gravity.”

But rather than mourn the loss, scientists held a briefing to celebrate the mission’s success.

“For the first time in history we now have real knowledge about the planet Mercury that shows it to be a fascinating world as part of our diverse solar system,” said John Grunsfeld, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington.

One of MESSENGER’s big findings: It sent back data indicating that ice in Mercury’s shadowed polar regions, if spread over an area the size of Washington, would be more than two miles thick, NASA said.

It also took some amazing photos of the planet.

So the MESSENGER mission is ending, but scientists say they’ll be busy for years studying data from the probe.

And if you want to see Mercury with your own eyes, you may be in luck if you can find an area with dark skies. It will be visible in the night sky just before dusk until about the end of May.

Your favorite astronomy website will have some helpful guides. Here are a few we found:

Earthsky.org

Astronomy

Sky and Telescope

Stardate