Pasquale Tricarico
Planetary Science Institute
1700 E. Fort Lowell Rd. #106
Tucson, AZ 85719

tel: +1 520 547-3954

Pasquale Tricarico, Ph.D.

Senior Scientist
Planetary Science Institute

Asteroid 2011 MD -- June 23, 2011

The asteroid 2011 MD, about 10 meters in diameter, will fly by the earth on Jun 27. I'm showing with these animations the geometry of this encounter. It is interesting to note that it will come closer than the GPS satellites, and also that it comes from the northern hemisphere, passes over the Earth's south pole, and then is deflected so strongly that it leaves the Earth returns to the northern hemisphere.

The first animation shows the passage of the asteroid from an observer far away, on the same plane of the Earth's orbit (while line left of the Earth). The Sun is to the left. The asteroid 2011 MD comes in from the top right corner (night side of the Earth), approaches the Earth at its minimum close to the south pole, and then leaves on the Earth's day side. Note how the orbit of the asteroid is perturbed by the Earth, so much so as to turn it around and send the asteroid almost back to where it comes from.

The second animation shows the same event, but from the point of view of the asteroid.

The next two animations include the GPS constellation. First from a fixed observer.

Finally, from the point of view of the asteroid. Notice how it crosses the GPS constellation.