NASA Tracked Small Asteroid Before It Broke Up in Atmosphere
The object never posed any harm but was an ideal test case for NASA planetary defense teams to test their alert system.
When a lightning detector on a NOAA weather satellite
detected something that wasn't lightning last Saturday, a scientist at the Center
for Near Earth Object Studies at NASA's Jet Propulsion Laboratory in Pasadena,
California, did some detective work.Could a tiny, harmless object that broke up in the
atmosphere in a bright flash be connected to a just-received automated alert of
a potential near-Earth asteroid discovery? Although far below the size that
NASA is tasked to detect and track, the event presented an ideal opportunity for
NASA planetary defense teams to test their parts of the alert system.The outcome? The flow of alert data works, and the culprit
was identified: It was an asteroid. Now designated 2019 MO, the asteroid was only
about 16 feet (5 meters) in size and was detected at 9:45 UTC (2:45 a.m. PDT, 5:45
a.m. EDT) on Saturday, June 22, by the University of Hawaii's ATLAS survey
telescope on Maunaloa in Hawaii.When first spotted, 2019 MO was about 310,000 miles (500,000
kilometers) from Earth - farther out than the orbit of our Moon. This was roughly
the equivalent of spotting something the size of a gnat from a distance of 310
miles (500 kilometers).The initial four observations by ATLAS were submitted to
the NASA-funded Minor Planet Center (the worldwide data processing node for
asteroid observations) and immediately assessed by automated impact-analysis
software, called Scout, at JPL. Scout quickly identified a possible impact. The
observations were too few to provide certainty but did show the size would be far
too small to be of concern."Asteroids this size are far smaller than what we're
tasked to track," said Davide Farnocchia, a scientist at the Center for
Near Earth Object Studies, which operates Scout. "They're so small, they
would not survive passing through our atmosphere to cause damage to Earth's
surface. But this event shows how capable our search programs are, even for
objects of such small sizes."Scout works by processing sky-position measurements of
each potential new asteroid and rapidly computing the possible range of future
motion even before these objects have been confirmed as discoveries.The mystery was closer to being solved in the early evening
of June 22, when a NOAA-NASA weather satellite called GOES-16 carrying aGeostationary
Lightning Mapperreported a possible bolide - the bright flash of an
asteroid impacting Earth's atmosphere - over the Caribbean Sea. JPL's
Farnocchia recognized that the object Scout flagged earlier that day could have
caused that bolide, and he dug into the data. He computed a viable trajectory
that would fit the coordinates of both the flash captured by the lightning mapper
and the ATLAS observations of about 12 hours earlier.Farnocchia noted the data on the tiny, new asteroid were
not yet conclusive: The body had been spotted only four times in just under
half an hour, which was not enough information to determine where the object
came from or exactly where it was headed.Luckily, the NASA-fundedPan-STARRS 2survey telescope on Maui had imaged the part of the sky where the small
asteroid could have been visible a couple of hours before the ATLAS
observations. Using the potential orbit Farnocchia had calculated, Pan-STARRS scientists Robert Weryk
and Mark Huber, both at the University of Hawaii Institute for Astronomy, and
Marco Micheli at the European Space Agency located the asteroid in images that
had been taken just before the ATLAS observations.With
these additional observations, a more precise trajectory for the asteroid was
calculated and the puzzle was solved: The object that impacted the atmosphere
over the Caribbean was the asteroid detected by ATLAS just 12 hours earlier and
flagged by Scout.The
impact of Asteroid 2019 MO has now been confirmed by international infrasound
and other US Government sensors and added to theCNEOS Fireball Map.JPL hosts the Center for Near-Earth Object Studies (CNEOS)
for NASA's Near-Earth Object Observations Program in NASA's Planetary Defense
Coordination Office.More
information about CNEOS, asteroids and near-Earth objects can be found at:https://cneos.jpl.nasa.govFor
more information about NASA's Planetary Defense Coordination Office, visit:https://www.nasa.gov/planetarydefenseFor
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