back to article NASA's Messenger craft SMASHES into Mercury: See ya later, alien crater

NASA's Messenger space probe has slammed into the planet Mercury at 3.9km per second (8,724mph) – creating the first human-made crater on the innermost planet of our solar system. Well I guess it is time to say goodbye to all my friends, family, support team. I will be making my final impact very soon. — MESSENGER (@ …

Go

Good job.

When the probe was proposed, the mission was considered a little daring—not too daring, but borderline. Considering the amount of data gathered, I am very happy they managed to get it on its way. So, goodbye MESSENGER. You did a great job. May many more probes follow you to refine what you found. RIP (Rust In Pieces), and thanks for a job well done.

That also goes for the people at NASA having planned and realised this mission, of course :)

5
0
Headmaster

Re: Good job.

"RIP (Rust In Pieces)"

Rust needs an oxygen environment to happen, which I'm not sure Mercury has And the probe needs to be made of iron, which it's probably not. :-)

But I agree wholeheartedly with your message.

1
0
Anonymous Coward

Next probe: The Kardashian Komet

At least that name will get it some main stream media time.

0
0
Silver badge
Mushroom

Ooops

There goes their no claim bonus.

0
0
Silver badge
Mushroom

Incoming!

1
0

Let's hope that there was nobody down there!

It seems to me that they have crashed Messenger into Mercury without any consideration of the poor Mercurian citizens living down there. How would we like it if a space probe from another world suddenly came thundering down on top of us. Even now I bet that they arming themselves for a retaliatory strike against us. Probably.

Still, the chances of anything coming from Mercury are substantially less than anything coming from Mars. Perhaps we should start building our cities underground. I have a plan !

:-)

1
0

Re: building our cities underground

This would also be handy for hiding from Shelks; I'm pretty sure we could hang on down there until Tumithak turns up to free us from the domination of Venus.

I think you mostly get Tetrahedra from Mercury. Underground cities are not required to deal with them, you just have to wait until it rains :-)

0
0
Silver badge

Re: Let's hope that there was nobody down there!

"the chances of anything coming from Mercury"

We're in trouble if it's 1,000,000:1

2
0

Dear engineers,

The Mercury Messenger probe lasted years beyond expected life span.

The Mars Opportunity Rover has gone 40 times over it's expected lifespan.

Why does my phone become obsolete every 12 months????

6
1
Silver badge

Re: Dear engineers,

Did you accept and install all those updates to 'improve your experience'?

2
0
Pint

Re: Dear engineers,

Define "obsolete". Your phone works as it always did. You just want a new shiny one.

Plus, MESSENGER wasn't sitting in your pocket with your keys scratching the screen, so is (was) probably as shiny as when it left orbit.

3
0
Gold badge

Re: Dear engineers,

If my phone 'works as it always did" then clearly the phone network's gotten worse. Damned thing drops calls 10 times a day. Never used to have that problem.

0
0

Ran out of fuel and crashed?

I don't understand that bit. If it ran out of fuel, surely it would stay in orbit round Mercury for ever, Mercury having no atmosphere to drag it down. We got past the notion of continual force being required for motion back in Isaac Newton's time.

Or did the controllers of the probe decide that they only had just enough fuel left to de-orbit it, and did that, probably according to plan?

0
1

Re: Ran out of fuel and crashed?

Presumably it will deorbit for the same reason that objects in Low Earth Orbit will. Things like solar wind and gravity perturbations eventually decay the orbit.

I think I read that they did in fact deliberately lower Messengers orbit so it would crash too.

The real universe is not like KSP where you can just sit in a 75km orbit for ever. ;)

2
0
Silver badge

Re: Ran out of fuel and crashed?

"I don't understand that bit. If it ran out of fuel, surely it would stay in orbit round Mercury for ever, Mercury having no atmosphere to drag it down. "

That is true if Mercury is a perfectly even sphere and you don't include the influence of other gravity sources in the solar system: the Sun especially, but I'd also look at Venus, Earth, and Jupiter for long-term tidal effects. Then there's light pressure and the solar wind.

The problem was first observed in the 1960s when the orbits of various Lunar orbiters tended to go awry. Luna, like Mercury, is not a perfectly even sphere. It has large mass concentrations (mascons) that send most satellites wandering off course over time.

Short wiki version (key words: "These anomalies are significant enough to cause a lunar orbit to change significantly over the course of several days"):

http://en.wikipedia.org/wiki/Lunar_orbit#Perturbation_effects

Historical version:

https://solarsystem.nasa.gov/scitech/display.cfm?ST_ID=2325

Uneven mass concentrations and external gravity loads can send satellites wandering. Apollo 16's PSF-2 lunar satellite was only in orbit 35 days. Geosynchronous satellites around Earth have to constantly use stationkeeping fuel to avoid drifting, and the non-spherical shape of Earth is a common consideration for orbital stability in other satellites. MESSENGER was becoming unpredictable; NASA wanted to crash it in a controlled fashion where they had the final say on its landing site for future science.

2
0
Boffin

Re: Ran out of fuel and crashed?

There aren't really any stable orbits around Mercury due to its proximity to the sun and Mercury's extremely elliptical orbit. In this scenario it's closer to a 3-body orbital system and MESSENGER needed to do a lot of stationkeeping to keep itself in the orbit it was in.

1
0
Silver badge

Re: Ran out of fuel and crashed?

"I don't understand that bit. If it ran out of fuel, surely it would stay in orbit round Mercury for ever"

Messenger was in an eliptical orbit which required a boost from its engine every few months to keep stable (due to the gravitational effect of the Sun.) Rather than deliberately crashing the probe into Mercury, mission controllers actually extended mission time by several weeks after all fuel was expended by venting Helium (previously used to pressurise the fuel supply) through the engine exhaust.

1
0
Silver badge

Mercury does have an atmosphere,

but a very very thin one that is normally hardly woth mentioning. Enough to cause drag on a satelite though

0
0
Anonymous Coward

Why crash on the far side?

Couldn't they save a bit of fuel to control the de-orbiting and make sure it crashed on the "near" side? Then you can get data feed till the last minute, and perhaps spectral data when it hits.

0
0

Re: Why crash on the far side?

It wasn't particularly maneuvarable, plus it's not always possible to predict precisely where it will hit in advance (the impact was the result of a gradual decay, not that they pointed the engines 'downwards' and plummeted straight in). There was presumably more science in prolonging the mission - the ony thing we didn't see is the impact. There also wouldn't have been any data transmissions (it's not a real-time camera broadcasting back, it takes pictures, processes, then transmits at the appropriate time).

Spectral data of impact - I assume we'd have needed it to be "side-on" to the planet from our perspective, and possibly in front of the sun to have something to read.

0
0

Re: Why crash on the far side?

There has been no 'spare fuel', Messenger ran completely OUT of fuel on April 20 (it was in the press). NASA prolonged the orbits 10 days further from using the fuel-pressurizer (Helium) and blowing it out the rocket nozzle (with no ignition).

They would have had to blast it downward back in March to get it to crash on the side facing Earth. They chose to collect data for a few weeks further, instead.

0
0

Last-but one orbit.

Messenger's penultimate orbit skimmed over the surface of Mercury at an altitude of between 300 and 600 metres.

"If you could see that, it would be a real spectacle," said Jim Raines, the instrument scientist on the craft's FIPS instrument (Fast Imaging Plasma Spectrometer) and a physicist at the University of Michigan. "It would cross the horizon in just a second or two, flying low overhead at ten times the speed of a supersonic fighter."

0
0

Sooner or later

A big ass alien dump truck is gonna pull up in orbit over nasa and return all out junk with a message along the lines of "Stop dumping your shit"

0
0

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Forums

Biting the hand that feeds IT © 1998–2017