Target Earth – A near miss by an asteroid

Asteroids have hit the Earth in the past, and astronomers are keeping an eye out for these objects.  While Earth gets hit by well over a ton of space dust and debris each day, most burns up in our atmosphere.  If chunks are larger than a few inches in size they have potential to reach the surface of our world.

An asteroid around 10 feet in diameter passed by the Earth on March 2 at 9am passing closer than many communications and weather satellites.  The asteroid, called 2017 EA reached within 9,000 miles (14,500 kilometers for those of you using correct units) of Earth.  Earth is about 8,000 miles (12,000 km) in diameter by comparison, so this was a relatively close shave.

NASA’s Center for Near-Earth Object Studies (CNEOS) predicts it will not be back in Earth’s neighborhood for over a 100 years.  The asteroid was first spotted around 6 hours prior to its closest approach by researches working on the Catalina Sky Survey in Arizona.   Many other observatories monitored it as well as it flew toward Earth.

The asteroid came in closer than the geosynchronous satellites which stay over one part of Earth as it turns. That orbit is good for providing communication services or monitoring one particular part of Earth’s surface.

If 2017 EA hit Earth rather than just passing by it might have caused some damage as the one which hit in Siberia on February 15, 2013 which blew out windows and was caught on dash board cameras.  That one called the Chelyabinsk meteor was most likely around 50 feet in diameter, but even ones the size of 2017 EA could do some damage. The exact effect would depend on the asteroid’s composition.

Although the asteroid was a stranger as it came in, its orbit around the Sun has now been calculated to a very high degree of accuracy, and researchers won’t get another close look for more than 100 years.

Asteroids a mile in diameter or larger are considered planet killers having the potential to cause climatic changes.  It is believed one about 2 miles in diameter struck the Yucatan peninsula and caused the extinction of the dinosaurs.

This month Emera Astronomy Center has a new program called Asteroid: Mission Extreme which looks at these objects in depth and explores the dangers and opportunities they might provide.  How might we protect Earth from threats of impacts?  What technology is being used to detect asteroids which pass close to our planet?  Could we use these object to our benefit?  These are a few of the questions the program seeks to explore.  The program will show at 7:00 pm every Friday during the month of March.  The planetarium will host a special Science Lecture Series event on April 6 featuring Dr. Hennig Haack who will explore Meteorites and the Origins of the Solar System which will feature part of the collection from the Maine Mineral and Gem Museum.

This year we have had a number of Near Earth Objects pass by, and many more will do so. For more information about these objects, check out NASA’s Near Earth Object Program.

Shawn Laatsch

About Shawn Laatsch

Shawn Laatsch is the director of the Emera Astronomy Center and Jordan Planetarium at the University of Maine. He started his astronomy education career in 1984 and has directed planetariums in university and science center facilities, taught undergraduate astronomy courses, and given numerous lectures around the globe. He serves as President (2017 & 2018) of the International Planetarium Society, Inc. the world’s largest organization of planetarium professionals. Shawn has a passion for sharing astronomy and stargazing with people of all ages.