Water on Mercury

[orin stepanek]

Hi! I was watching the science channel today; and they say there is water Ice on Mercury's North Pole. I found this writeup on the net. http://findarticles.com/p/articles/mi_m ... _11570759/
I always figured Mercury to be too hot for water of any kind. 8)

Orin

[neufer]

Hi! I was watching the science channel today; and they say there is water Ice on Mercury's North Pole. I found this writeup on the net. http://findarticles.com/p/articles/mi_m ... _11570759/
I always figured Mercury to be too hot for water of any kind. 8)

With an axial tilt of just 0° 2.1′ there is no summertime inside of dark Mercurial polar craters.
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<<Mercury, the innermost planet of our Solar System, is less than half as distant from the Sun as the Earth. Because of this proximity, parts of Mercury's surface are heated to temperatures nearing 425 degrees Celsius (800 degrees Farenheit). Thus, it was long considered one of the least likely places to find ice.

In 1991, planetary scientists Duane Muhleman and Bryan Butler from Caltech and Martin Slade from the Jet Propulsion Laboratory, studied Mercury using a radar system consisting of a 70-meter (230-foot) dish antenna at Goldstone, CA, equipped with a half-million-watt transmitter, and the VLA as the receiving system. The beam of 8.5-GHz microwaves sent from Goldstone bounced off Mercury and was collected at the VLA to produce a radar image of the planet. The researchers used the Goldstone-VLA radar system to look at the side of Mercury that was not photographed by Mariner 10.

The resulting radar image, shown here,

contained a stunning surprise. In this image, red indicates strong reflection of the radar signal and yellow, green, and blue, progressively weaker reflection. The bright red dot at the top of the image indicates strong radar reflection at Mercury's north pole. In fact, it resembles the strong radar echo seen from the ice-rich polar caps of Mars.

"Normal" ice, such as that found on Earth, absorbs radio waves, but ice at very low temperatures is a very effective reflector of radio waves. The strong reflection seen on Mercury is too large to be caused by a momentary "glint" off a crater wall, and when studied in more detail shares the characteristics of reflections from the water ice seen on Mars and the icy moons of Jupiter.

Scientists now believe that the ice resides on the floors of craters at Mercury's north pole, where it can remain permanently shaded from the Sun and reach temperatures as low as 125 degrees Kelvin (-235 degrees Farenheit).

The VLA, with its great angular resolution, or ability to see fine detail, was crucial to this discovery. It was able to provide sufficient detail of small regions (down to 100 meters in this observation) to reveal the ice reflections. Other analytical capabilities of the VLA helped to further confirm the discovery. In 1994, the same observing team discovered a similar radar reflection from Mercury's south pole.>>

[Martin]

We must collect a sample of this Mercury Ice.

[neufer]

We must collect a sample of this Mercury Ice.

It is probably just cometary ice that has collected over the eons.

Without the gravitational assist of Jupiter it takes a great deal of energy (and/or time) just to orbit Mercury much less to retrieve a sample from same. It is much easier to first retrieve ice samples directly from comets or from dark lunar polar craters.

[orin stepanek]

We must collect a sample of this Mercury Ice.

It is probably just cometary ice that has collected over the eons.

Without the gravitational assist of Jupiter it takes a great deal of energy (and/or time) just to orbit Mercury much less to retrieve a sample from same. It is much easier to first retrieve ice samples directly from comets or from dark lunar polar craters.

Luna probably would be an easier place to look for ET than on Mars though. Could be a good thing to check for before using It as a solution for a water supply on a possible Lunar or even Martian base.
I guess it is even harder to get a probe to Mercury than to Jupiter because of the close proximity to the sun.

Orin

[neufer]

Without the gravitational assist of Jupiter it takes a great deal of energy (and/or time) just to orbit Mercury much less to retrieve a sample from same. It is much easier to first retrieve ice samples directly from comets or from dark lunar polar craters.

Luna probably would be an easier place to look for ET than on Mars though. Could be a good thing to check for before using It as a solution for a water supply on a possible Lunar or even Martian base.

Plus, they sing to you and give you free cheese: http://tinyurl.com/mfba84

I guess it is even harder to get a probe to Mercury than to Jupiter because of the close proximity to the sun.

For every one unit of energy it takes to climb out of earth's potential well to get to Jupiter
it takes TWO units of energy to slow down so as to drop into Mercury's deep potential well:

Code: Select all

-[47.87 km/s]^2 ~ -2292 : Mercury orbital energy
-[29.78 km/s]^2 ~  -887 : Earth orbital energy
-[13.07 km/s]^2 ~  -171 : Jupiter orbital energy
-[5.43 km/s]^2 ~   -30 : Neptune orbital energy

However, If one has the patience there is plenty of solar energy to use for ion rockets (or solar sails).

[aristarchusinexile]

Just shows to go you, ice on Mercury might mean life on Mercury .. and "they said it couldn't be done."

[orin stepanek]

[quoteFor every one unit of energy it takes to climb out of earth's potential well to get to Jupiter
it takes TWO units of energy to slow down so as to drop into Mercury's deep potential well:
][/quote][quote by neufer on Thu Jun 25, 2009 9:26 pm][/quote]

Isn't that why Messenger is gradually being brought into orbit around Mercury?

Orin

[neufer]

For every one unit of energy it takes to climb out of earth's potential well to get to Jupiter
it takes TWO units of energy to slow down so as to drop into Mercury's deep potential well:

Isn't that why Messenger is gradually being brought into orbit around Mercury?

Yes; it is a fascinating billiard shot!

Each new orbital period must be a simple fraction (or multiple) of the planetary
orbital period so that the returning orbital intersections occur simultaneously: