Came across this site the other day and thought it would be good to share:
Of interest was the “Fly to Mars” web app, where you attempt to time your launch from Earth so it arrives at Mars.
Great way to kill a few hours during a slow day!
Hi! Got a question for you: NASA’s STEREO CORE2 – A (ahead) sat cam has recently been taking pictures of the sun in which there appears to be an anomalous energetic body, moving toward the sun. It is huge, and it is moving the wrong way for it to be Venus… Any thoughts on just what we’re looking at? Inquiring …minds wish to know Here is link: (please note the “STEREO Ahead Core2″ photo: http://stereo-ssc.nascom.nasa.gov/browse/2010/04/25/
Very good question Rogan!
From the STEREO site:
Also, comets hitting the sun are not an unheard of occurrence.
Check this link, from SOHO.
While this isn’t my field of study, I would have to surmise, based on the similarities between the STEREO Ahead CORE2 image you provided the link to, and the SOHO data, the object you are asking about is Mercury.
So here’s an interesting thought exercise:
If the sun disappeared in the blink of an eye, how long would it take for people on earth to notice, and what would happen to the earth?
Here’s one response:
Well considering the gravitational implications and the very frail balance of our specific distance from the sun, I’d say we’d notice pretty instantly…but the question is would we freeze before we knew it?
This is a good thought, and brings up the point of the exercise:
“Does gravity propagate instantly, or at the speed of light?”
Since our Sun is eight light minutes away from us, if it “suddenly” vanished, we wouldn’t know for about eight minutes. Current observations tell us that gravity does propagate at light speed (+/- 10% error)
Following up on yesterday’s question, I had forgotten to post more information about Stellarium.
From their site:
Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope. It is being used in planetarium projectors. Just set your coordinates and go.
Did I mention Stellarium is FREE? Learn more at: