Question

Ok, below is a question sent to me from one of the members of the SIAR:

"I have a small quandary. I've assigned my students to look up
some basic info on the planets via the web. Then I tried to create
the answer key, and found VERY contradictory info regarding
Mercury from assorted, reputable sources. It seems that online
info indicates Mercury's surface gravity is 0.28 G, 0.33 G, or
0.38 G (virtually identical to Mars).

Do you have some info on this? Is there a solid, definitive answer?"

What you all say?


--

The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
Astronomy Net Online Gift Shop
http://www.cafepress.com/astronomy_net

On Mon, 22 Aug 2005 20:07:48 -0700, "Starlord"
wrote:

Ok, below is a question sent to me from one of the members of the SIAR:

"I have a small quandary. I've assigned my students to look up
some basic info on the planets via the web. Then I tried to create
the answer key, and found VERY contradictory info regarding
Mercury from assorted, reputable sources. It seems that online
info indicates Mercury's surface gravity is 0.28 G, 0.33 G, or
0.38 G (virtually identical to Mars).

Do you have some info on this? Is there a solid, definitive answer?"

What you all say?

Lang gives a value of 3.7 m/s^2, or 0.38G. You can test this, using

A = Mp / Rp^2 * Ae
(Mp, Rp are mass and radius relative to Earth, Ae is Earth's gravity)

A = 0.05527 / 0.382^2 * 9.8 m/s^2 = 3.71 m/s^2 = 0.38G

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

I'll pass it on to him.


--

The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
Astronomy Net Online Gift Shop
http://www.cafepress.com/astronomy_net



"Chris L Peterson" wrote in message
...
On Mon, 22 Aug 2005 20:07:48 -0700, "Starlord"
wrote:

Ok, below is a question sent to me from one of the members of the SIAR:

"I have a small quandary. I've assigned my students to look up
some basic info on the planets via the web. Then I tried to create
the answer key, and found VERY contradictory info regarding
Mercury from assorted, reputable sources. It seems that online
info indicates Mercury's surface gravity is 0.28 G, 0.33 G, or
0.38 G (virtually identical to Mars).

Do you have some info on this? Is there a solid, definitive answer?"

What you all say?

Lang gives a value of 3.7 m/s^2, or 0.38G. You can test this, using

A = Mp / Rp^2 * Ae
(Mp, Rp are mass and radius relative to Earth, Ae is Earth's gravity)

A = 0.05527 / 0.382^2 * 9.8 m/s^2 = 3.71 m/s^2 = 0.38G

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Chris L Peterson wrote:

On Mon, 22 Aug 2005 20:07:48 -0700, "Starlord"
wrote:

Ok, below is a question sent to me from one of the members of the SIAR:

"I have a small quandary. I've assigned my students to look up
some basic info on the planets via the web. Then I tried to create
the answer key, and found VERY contradictory info regarding
Mercury from assorted, reputable sources. It seems that online
info indicates Mercury's surface gravity is 0.28 G, 0.33 G, or
0.38 G (virtually identical to Mars).

Do you have some info on this? Is there a solid, definitive answer?"

What you all say?

Lang gives a value of 3.7 m/s^2, or 0.38G. You can test this, using

A = Mp / Rp^2 * Ae
(Mp, Rp are mass and radius relative to Earth, Ae is Earth's gravity)

A = 0.05527 / 0.382^2 * 9.8 m/s^2 = 3.71 m/s^2 = 0.38G


NASA's Planetary Fact Sheet at

http://nssdc.gsfc.nasa.gov/planetary/factsheet/mercuryfact.html

agrees, giving 3.70 m/s^2 = 0.378 gee.

--
Odysseus