NASA Refines Asteroid Apophis' Path Toward Earth

Oct 07, 2009
Asteroid Apophis was discovered on June 19, 2004. Image credit: UH/IA

(PhysOrg.com) -- 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 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 2.2-meter (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 2.3 meter (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 29,450 kilometers (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 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. JPL is a division of the California Institute of Technology in Pasadena. Cornell University, Ithaca, N.Y., 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: www.jpl.nasa.gov/asteroidwatch

Provided by JPL/NASA (news : web)

Explore further: Bright points in Sun's atmosphere mark patterns deep in its interior

add to favorites email to friend print save as pdf

Related Stories

NASA Statement on Student Asteroid Calculations

Apr 17, 2008

The Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., has not changed its current estimates for the very low probability (1 in 45,000) of an Earth impact by the asteroid ...

NASA to Provide Web Updates on Objects Approaching Earth

Jul 30, 2009

NASA's Jet Propulsion Laboratory is introducing a new Web site that will provide a centralized resource for information on near-Earth objects - those asteroids and comets that can approach Earth. The "Asteroid ...

Asteroid is 'practice case' for potential hazards

Oct 12, 2007

In research that could aid decisions about future asteroids on a collision course with Earth, MIT researchers have for the first time determined the composition of a near-Earth asteroid that has a very slight possibility ...

Asteroid to Make Rare Close Flyby of Earth

Jan 24, 2008

Scientists are monitoring the orbit of asteroid 2007 TU24. The asteroid, believed to be between 150 meters (500 feet) and 610 meters (2,000 feet) in size, is expected to fly past Earth on Jan. 29, with its ...

NASA Scientists Get First Images of Earth Flyby Asteroid

Jan 28, 2008

Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., have obtained the first images of asteroid 2007 TU24 using high-resolution radar data. The data indicate the asteroid is somewhat asymmetrical ...

Recommended for you

Ceres and Vesta Converge in Virgo

2 hours ago

Don't let them pass you by. Right now and continuing through July, the biggest and brightest asteroids will be running on nearly parallel tracks in the constellation Virgo and so close together they'll easily ...

A full-spectrum Mars simulation in a box

2 hours ago

There are many reasons why Mars excels at destroying expensive equipment. For one thing, its entire surface is made of partially-magnetized dust. For another, Mars possesses just enough atmosphere so that ...

LADEE mission ends with planned lunar impact

2 hours ago

(Phys.org) —Ground controllers at NASA's Ames Research Center in Moffett Field, Calif., have confirmed that NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft impacted the surface ...

Proposed Mars 'Icebreaker' mission detailed

3 hours ago

Scientists supported by the Astrobiology Technology for Exploring Planets (ASTEP) and Astrobiology Instrument Development Programs (ASTID) have outlined the proposed 'Icebreaker' mission to Mars in a recent ...

User comments : 6

Adjust slider to filter visible comments by rank

Display comments: newest first

axemaster
1 / 5 (1) Oct 07, 2009
"The Apophis asteroid is approximately the size of two-and-a-half football fields."

Uh huh... And how big is a football field? How is this supposed to mean anything?
sender
3 / 5 (2) Oct 07, 2009
Let's catch this thing in space!
drel
4 / 5 (1) Oct 08, 2009
"The Apophis asteroid is approximately the size of two-and-a-half football fields."

Uh huh... And how big is a football field? How is this supposed to mean anything?


Q- how big is a football field?
A- American football field is 360 feet x 160 feet.

Q- How is this supposed to mean anything?
A- Exactly, a "football field" is an area. It says nothing as to the volume or mass of the asteroid. one could assume that the third dimensional measurement is less than 160 feet, but you know what happens when you assume...
Velanarris
not rated yet Oct 08, 2009
A football field is 100 yards long. Apophis' diameter is 250 yards.

You can get a relatively accurate volume assuming Apophis is approximately round through standard algebra.

To your second point, we'd have to know what apophis is made of to really know the potential fall out, and last I knew the estimates were that apophis is carboneferous rock, Carbon and Iron, so it would be very damaging if it made contact with the planet.
Hernan
not rated yet Oct 08, 2009
Check out this link for detailed information : http://ssd.jpl.na...42;orb=1
LuckyBrandon
not rated yet Oct 10, 2009
"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

why in the hell dont they just say "from 1 in 45000 to 1 in 250,000"...
does 4 in a million make it sound more impressive to anyone here im curious....?

More news stories

Continents may be a key feature of Super-Earths

Huge Earth-like planets that have both continents and oceans may be better at harboring extraterrestrial life than those that are water-only worlds. A new study gives hope for the possibility that many super-Earth ...

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Under some LED bulbs whites aren't 'whiter than white'

For years, companies have been adding whiteners to laundry detergent, paints, plastics, paper and fabrics to make whites look "whiter than white," but now, with a switch away from incandescent and fluorescent lighting, different ...