Author Topic: NASA Refines Asteroid Apophis' Path Toward Earth  (Read 4188 times)

Offline jacqmans

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NASA Refines Asteroid Apophis' Path Toward Earth
« on: 10/07/2009 06:54 PM »
RELEASE: 09-232

NASA REFINES ASTEROID APOPHIS' PATH TOWARD EARTH

PASADENA, Calif. -- Using updated information, NASA scientists have
recalculated the path of a large asteroid. The refined path indicates
a significantly reduced likelihood of a hazardous encounter with
Earth in 2036.

The Apophis asteroid is approximately the size of two-and-a-half
football fields. The new data were documented by near-Earth object
scientists Steve Chesley and Paul Chodas at NASA's Jet Propulsion
Laboratory in Pasadena, Calif. They will present their updated
findings at a meeting of the American Astronomical Society's Division
for Planetary Sciences in Puerto Rico on Oct. 8.

"Apophis has been one of those celestial bodies that has captured the
public's interest since it was discovered in 2004," said Chesley.
"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."

A majority of the data that enabled the updated orbit of Apophis came
from observations Dave Tholen and collaborators at the University of
Hawaii's Institute for Astronomy in Manoa made. Tholen pored over
hundreds of previously unreleased images of the night sky made with
the University of Hawaii's 88-inch telescope, located near the summit
of Mauna Kea.

Tholen made improved measurements of the asteroid's position in the
images, enabling him to provide Chesley and Chodas with new data sets
more precise than previous measures for Apophis. Measurements from
the Steward Observatory's 90-inch Bok telescope on Kitt Peak in
Arizona and the Arecibo Observatory on the island of Puerto Rico also
were used in Chesley's calculations.

The information provided a more accurate glimpse of Apophis' orbit
well into the latter part of this century. Among the findings is
another close encounter by the asteroid with Earth in 2068 with
chance of impact currently at approximately three-in-a-million. As
with earlier orbital estimates where Earth impacts in 2029 and 2036
could not initially be ruled out due to the need for additional data,
it is expected that the 2068 encounter will diminish in probability
as more information about Apophis is acquired.

Initially, Apophis was thought to have a 2.7 percent chance of
impacting Earth in 2029. Additional observations of the asteriod
ruled out any possibility of an impact in 2029. However, the asteroid
is expected to make a record-setting -- but harmless -- close
approach to Earth on Friday, April 13, 2029, when it comes no closer
than 18,300 miles above Earth's surface.

"The refined orbital determination further reinforces that Apophis is
an asteroid we can look to as an opportunity for exciting science and
not something that should be feared," said Don Yeomans, manager of
the Near-Earth Object Program Office at JPL. "The public can follow
along as we continue to study Apophis and other near-Earth objects by
visiting us on our AsteroidWatch Web site and by following us on the
@AsteroidWatch Twitter feed."

The science of predicting asteroid orbits is based on a physical model
of the solar system which includes the gravitational influence of the
sun, moon, other planets and the three largest asteroids.

NASA detects and tracks asteroids and comets passing close to Earth
using both ground and space-based telescopes. The Near Earth-Object
Observations Program, commonly called "Spaceguard," discovers these
objects, characterizes a subset of them and plots their orbits to
determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science
Mission Directorate in Washington. Cornell University operates the
Arecibo Observatory under a cooperative agreement with the National
Science Foundation in Arlington, Va.

For more information about asteroids and near-Earth objects, visit:



http://www.jpl.nasa.gov/asteroidwatch


For more information about NASA, visit:



http://www.nasa.gov

Offline Aeroman

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Re: NASA Refines Asteroid Apophis' Path Toward Earth
« Reply #1 on: 10/07/2009 07:00 PM »
Would this asteroid qualify for a NEO spacecraft visit since it is gonna be only about 18,000 miles from earth at closest approach?

Offline iamlucky13

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Re: NASA Refines Asteroid Apophis' Path Toward Earth
« Reply #2 on: 10/07/2009 10:15 PM »
Since it has a relatively circular orbit, it's not going to zoom by at high speed, which is as much of a consideration as its distance. It seems to me it should be a pretty good target, but I believe there's even better candidates.

If you're thinking about a manned mission to it as has been discussed in relation to ESAS, keep in mind that it's 18,000 miles away only very briefly. A lander would need to catch it some where out around the distance of the moon in order to have a worthwhile amount of time to study it.

Offline simonbp

Re: NASA Refines Asteroid Apophis' Path Toward Earth
« Reply #3 on: 10/13/2009 03:26 AM »
At the presentation, they said the "impact window" for the 2036 chance is very small (half km, IIRC), but is right along the projected path, while 2068 has a larger window, with a looser correlation the projected trajectory. Either way, the chance was 3x10^-6 of an impact.

They (and others in the session) made the point that if we do detect a major impact hazard, it will be right before an impact, when the bolide is on its "death plunge" to Earth. So, the more worthwhile preparations may be evacuation plans, rather than deflection...

I wonder who made the observations at the Bok; it's usually reserved for grad students in Arizona universities...
« Last Edit: 10/13/2009 03:27 AM by simonbp »

Offline bolun

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Re: NASA Refines Asteroid Apophis' Path Toward Earth
« Reply #4 on: 01/10/2013 08:47 PM »
Herschel intercepts asteroid Apophis

9 January 2013

ESA’s Herschel space observatory made new observations of asteroid Apophis as it approached Earth this weekend. The data shows the asteroid to be bigger than first estimated, and less reflective.

Catalogued as asteroid (99942) Apophis (previously 2004 MN4), it is often nicknamed ‘the doomsday asteroid’ in popular media, after initial observations made after its discovery in 2004 gave it a 2.7% chance of striking Earth in April 2029.

With additional data, however, an impact in 2029 was soon ruled out, although the asteroid will pass within 36 000 km of Earth’s surface, closer even than the orbits of geostationary satellites.

The asteroid will return to Earth’s neighbourhood again in 2036, but quite how close it will come then is uncertain, as the 2029 approach is predicted to alter its orbit substantially. Obtaining improved physical parameters for Apophis and its orbit is thus of great importance in being able to make better predictions of its future trajectory.

http://www.esa.int/Our_Activities/Space_Science/Herschel_intercepts_asteroid_Apophis

Offline Prober

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Re: NASA Refines Asteroid Apophis' Path Toward Earth
« Reply #5 on: 01/11/2013 11:53 PM »
Since it has a relatively circular orbit, it's not going to zoom by at high speed, which is as much of a consideration as its distance. It seems to me it should be a pretty good target, but I believe there's even better candidates.

If you're thinking about a manned mission to it as has been discussed in relation to ESAS, keep in mind that it's 18,000 miles away only very briefly. A lander would need to catch it some where out around the distance of the moon in order to have a worthwhile amount of time to study it.

we have enough time to plan a decent mission.   

One mission yet to be done is to use a traveling Asteroid as a "station".  Land a communications transfer station.   A telescope to travel with the Aseroid as a base and do work from the that point of view.   
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Offline Ben the Space Brit

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Re: NASA Refines Asteroid Apophis' Path Toward Earth
« Reply #6 on: 01/14/2013 01:54 PM »
[One mission yet to be done is to use a traveling Asteroid as a "station".  Land a communications transfer station.   A telescope to travel with the Aseroid as a base and do work from the that point of view.   

Given that Apophis is a long-term PHO, I'd personally like to attach a solar-powered radio beacon on the asteroid so it can be properly tracked throughout its orbit and we can have a really good handle on its orbital path and likely interactions with Earth and the Moon for the next few dozen cycles.
« Last Edit: 01/14/2013 01:54 PM by Ben the Space Brit »
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Offline JohnFornaro

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Re: NASA Refines Asteroid Apophis' Path Toward Earth
« Reply #7 on: 01/16/2013 02:33 AM »
Given that Apophis is a long-term PHO, I'd personally like to attach a solar-powered radio beacon on the asteroid so it can be properly tracked throughout its orbit and we can have a really good handle on its orbital path and likely interactions with Earth and the Moon for the next few dozen cycles.

That's not a bad idea at all.  Write up a proposal.  There's a good chap.
Sometimes I just flat out don't get it.

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