Apophis Travel Time To Earth:


Apophis Asteroid collision with Earth possibility


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When in January 2004, a team of astronomers led by Lance Benner of JPL (Jet Propulsion Laboratory in Pasadena, CA) pinged 2004 MN4 (back then it wasn't called 99942 Apophis just yet) using the giant Arecibo radio telescope, echoes did reveal the asteroid's precise distance and velocity "allowing us to calculate the details of the 2029 flyby," said Jon Giorgini, who was a member of the team along with Benner, Mike Nolan (Arecibo Observatory, staff scientist) and Steve Ostro (JPL). Although, since usage of the Arecibo Observatory radio telescope astronomers have undoubtedly known that Apophis would be missing the Earth; what the additional data gathered has confirmed is that on April 13, 2029 humanity will have an extremely rare and spectacular sky gazing show. "At closest approach, the asteroid will shine like a 3rd magnitude star, visible to the unaided eye from Africa, Europe and Asia... even through city lights", says Giorgini. How rare is this? This is so rare that "close approaches by objects as large as 2004 MN4 (Apophis) are currently thought to occur at 1000 year intervals, on average", he continued. Literally, this is a once in lifetime opportunity to see such a historic asteroid event. That is, if, one believes that the 2029 Apophis approach will be its closest in this millennium. Not all scientists agree.

The asteroid's trajectory will bend approximately 28 degrees during the 2029 encounter. This is "a result of Earth's gravitational pull", explains Giorgini. What happens next is uncertain.

Some newspapers have stated that Apophis might swing around and hit the Earth after all in 2035-2036 or so. But, Giorgini quickly discounted this notion in 2004 by stating "Our ability to 'see' where 2004 MN4 will go (by extrapolating its orbit) is so blurred out by the 2029 Earth encounter, it can't even be said for certain what side of the sun 2004 MN4 will be on in 2035. Talk of an Earth encounter in 2035 (2036) is premature." Thus, some uncertainty will linger on.

However, since all of the initial excitement after the discovery of Apophis back in 2004, astronomers have now made major improvements in their ability to estimate the trajectory of its orbit. New calculations about the possibility of an April 13, 2036 asteroid impact with our planet by near-Earth object scientists Steve Chesley and Paul Chodas of the Jet Propulsion Laboratory have given comfort to many with their updated findings. Using data primarily gathered from the observations of Dave Tholen and his fellow astronomers at the University of Hawaii's Institute for Astronomy in Manoa, along with measurements from the Steward Observatory's 90-inch Bok telescope on Kitt Peak in Arizona, and the Arecibo Observatory in Puerto Rico, Chesley stated: "Updated computational techniques and newly available data indicate the probability of an Earth encounter on April 13, 2036, for Apophis has dropped from one-in-45,000, to about four-in-a million." Those are great odds in favor of Apophis not hitting Earth. Nevertheless, there's always skeptics and those who'll say that the real threat is 2029.

What many scientists do agree on, however, is that Apophis does warrant closer scrutiny. With this in mind, the Planetary Society of Pasadena, CA (co-founded by Carl Sagan, Bruce Murray, and Louis Friedman) in February 2008 awarded $50,000 in prize money to companies and students who submitted designs for space probes that could put a tracking device on or near Apophis. In what was called, the Apophis Mission Design Competition, seven winners were selected. First place went to a team led by SpaceWorks Engineering, Inc. of Atlanta, Georgia in conjunction with SpaceDev, Inc. of Poway, California for their mission, entitled Foresight. The Georgia Institute of Technology, also coincidentally in Atlanta, Georgia, took first place in the student category winning $5,000 for Jonathan Sharma, a student at the Daniel Guggenheim School of Aerospace Engineering, for a mission design project entitled Pharos.

April 13, 2029, will be a special day as we have a rare opportunity to see an asteroid so close. Although, the view through small optical telescopes won't be so good (a starlike point in all but the largest), to the naked eye it'll be the brightest asteroid you will ever have a chance to see!

Rusty Schweickart (an Apollo 9 astronaut and co-founder of the B612 Foundation) speaks about 99942 Apophis (2004MN4) 2009 pass-by and the need for development of asteroid impact protection program for 2036.