There are currently about 1,121 known PHAs.

There are about 7,045 known near earth asteroids

PHAs are Potentially Hazardous Asteroids - Data courtesy of NASA's Near Earth Object Observations Program

Discovery of PHA 2009 BD81 by ARO

Link to ARO images of fast moving NEO K09D10U.htm

Current NEO Observation program News

The Tracking News

NEO Follow-up Project - Overview

Students who participate in NASA's Near Earth Object Observations Program will receive acknowledgement by the Astronomical Research Institute for each NEO they report measurements on using data from the NEO Follow-up Project. You can find the 2009-2010 table of NEO Follow-up Program involving students and teachers worldwide on the Killer Asteroid Project website. The International Asteroid Search Campaign provides a vital role in helping students learn valuable techniques in NEO measurements. Learn more about how we provide NEO images for teacher and student educational programs.

So why study Near Earth Objects in the first place? Because there is a possible threat that the Earth could be struck by an asteroid in the future. See movies and interesting information about Apophis a near earth object close approach in 2029 and a very slim possibility for a potential impact in 2036!

Potentially Hazardous Asteroids (PHAs) are currently defined based on parameters that measure the asteroid's potential to make threatening close approaches to the Earth. Specifically, all asteroids with an Earth Minimum Orbit Intersection Distance (MOID) of 0.05 AU or less and an absolute magnitude (H) of 22.0 or less are considered PHAs. In other words, asteroids that can't get any closer to the Earth (i.e. MOID) than 0.05 AU (roughly 7,480,000 km or 4,650,000 mi) or are smaller than about 150 m (500 ft) in diameter (i.e. H = 22.0 with assumed albedo of 13%) are not considered PHAs.

This ``potential'' to make close Earth approaches does not mean a PHA will impact the Earth. It only means there is a possibility for such a threat on a date in the future. By monitoring these PHAs and updating their orbits as new observations become available, we can better predict the close-approach statistics and thus their potential Earth-impact threat.

The NEO Follow-Up Project involves conducting Near Earth Object Observations of new objects as they are discovered by the large survey telescopes such as LINEAR, the Catalina Sky Survey, LONEOS, SpaceWatch and others. This is a relatively easy project that takes a small amount of time to learn and students will see results very quickly.

NEO data on newly discovered objects is published at the Minor Planet Center (MPC) and on the NASA/JPL Horizons website. Our goal to make as many observations of these newly discovered objects as possible. Once all of these objects have been imaged, we will follow-up on other NEOs that have not been seen recently. The NEO Follow-up Project will attempt to recover NEOs that are listed on the MPC Bright Recovery Opportunities and Faint Recovery Opportunties. Some of these objects have not been seen for many years. Each month the Astronomical Research Institute provides the MPC with the positions on dozens of asteroids. This is real science and research for NASA's NEO Observations Program that can easily be accomplished by instructor and student researchers. This research along with student measures will make real contribution to science so the orbits of known Near Earth Objects will be better defined.

In the NEO Follow-Up Project, you will learn how to generate minor planet orbits and print out the expected coordinates of your target NEO. With powerful software you will be able to complete reports that will be sent to the Minor Planet Center enabling astronomers to refine orbital elements by fitting our observations to these known objects.

For complete details, software and manuals for conducting Near Earth Object Observations in your classroom, contact Robert Holmes, PI at the Astronomical Research Institute's contact page. There is no cost to any students or teachers for participation in this exciting research program.

Contributions of observations by the Astronomical Research Observatory are published in the IAU Electronic Circulars and in the Minor Planet Center's Electronic Circulars.

This project is funded by NASA grant Grant Number EPO-07-813.

Back to Home Page