- 3878 - METEOR - likely Earth impacts? A sizable space rock will make its closest approach to Earth in four centuries on Wednesday evening, February 15, 2023, but it will miss us. A Valentine's kiss.
--------------------- 3878 - METEOR - likely Earth impacts?
- The
near-Earth asteroid 2005 YY128 will zoom within 2.8 million miles of our planet at 3:46 p.m. PST on Wednesday
closer than it's gotten to us in more than 400 years. Listen for the swissssh!
-
- That's about
12 times the distance from Earth to the moon.
As its name suggests, 2005 YY128 was discovered in 2005, by astronomers
at Kitt Peak Observatory in southern Arizona. Over the past 17 years,
researchers have mapped its orbit with a high degree of precision.
-
- Their
observations, however, haven't nailed down 2005 YY128's size. The best
astronomers can give us is a diameter range, somewhere between 1,903 feet and
4,265 feet.
-
- 2005 YY128
therefore qualifies as a potentially hazardous asteroid, a designation given to
space rocks at least 460 feet wide whose orbits take them within 0.05
astronomical units (AU) of our planet.
-
- One AU is
the average Earth-sun distance, 93 million miles, or 150 million km. So 0.05 AU
is roughly 4.6 million miles.
-
- If 2005
YY128 did slam into Earth, it would do serious damage. The largest near-Earth asteroids (> 1 km
diameter) have the potential to cause geologic and climate effects on a global
scale, disrupting human civilization and perhaps even resulting in extinction
of the species.
-
- Smaller
NEOs [near-Earth objects] in the 140-meter to 1-km size range could cause
regional up to continental devastation, potentially killing hundreds of
millions.
-
- 2005 YY128's
close approach comes on a fateful day, the 10th anniversary of the Chelyabinsk
airburst. On February 15, 2013, a
65-foot-wide space rock exploded without warning over the Russian city of
Chelyabinsk, shattering thousands of windows and causing minor injuries on the
ground (mostly from flying shards of broken glass).
-
- The incident
highlighted the importance of better understanding the NEO population, it's only a matter of time before a truly
dangerous asteroid lines Earth up in its crosshairs.
-
- As a
result, scientists are getting a better and better handle on the NEO
population. NASA and its partners have
found more than 95% of the asteroids out there at least 0.6 miles (1 km) wide
that are thought to come within 30 million miles (50 million km) of Earth at
some point. And none of them pose a danger for the foreseeable future.
-
- On February
15, 2013 NASA was preparing for a TV segment on the flyby of a near-Earth
asteroid, 2012 DA14, which was expected to zoom within 17,200 miles of Earth. As it turned out, the videos sent showed a
59-foot near-Earth asteroid exploding in the atmosphere after surprising
scientists by coming from the direction of the sun, a blind spot for telescopes
and other sensors on the ground.
-
- The resulting
explosion caused millions of dollars of damage throughout Chelyabinsk and
injured thousands of residents across an area hundreds of miles wide. Most
injuries were caused by broken glass, although hundreds of Chelyabinsk
residents suffered eye damage from the blast that briefly lit up the skies more
brightly than the sun. A few dozen reported burns from the intense ultraviolet
radiation caused by the blast.
-
- Ten years
later, the Chelyabinsk meteor explosion and the damage it caused underscore the
need for asteroid-tracking telescopes such as NASA's “NEO Surveyor”, planetary
defense missions such as the Double Asteroid Redirection Test, and research
organizations like the CNEOS.
-
- While
there are currently no known asteroids that are on a collision course with
Earth, unexpected objects routinely crash into the atmosphere with only a few
hours notice. And in the case of Chelyabinsk, sometimes asteroids can arrive
undetected through blind spots in our detection capabilities.
-
- After the
Chelyabinsk meteor exploded, infrasound sensors designed to detect nuclear
detonations helped scientists determine that the blast was indeed incredibly
powerful.
-
- Initially,
the explosion was estimated to be between 300 and 400 kilotons, but more recent
estimates put the size at 500 kilotons. By comparison, the Fat Man nuclear
warhead dropped on the Japanese city of Nagasaki during World War II had a
yield of 21 kilotons.
-
- While
smaller meteor impacts and fireballs are somewhat common, impacts such as
Chelyabinsk or the Tunguska event 100 years prior are far rarer due to the fact
that larger objects are exponentially less common throughout the solar system
than smaller ones.
-
- Small
objects hit us every day. You can go out and see meteor showers, and those are
little pebble-sized objects, which are extremely numerous. That's why those
impacts are common. And that's a hard thing to understand. As you go up to
larger and larger sizes, the impacts become less and less frequent.
-
- A hole,
thought to be made by the fragment of the meteor in the ice of Chebarkul Lake
is seen on Feb. 16, 2013, some 50 miles from Chelyabinsk, Russia. The local
government reported more than 1,100 people injured, mostly by flying glass
broken by the shock wave of the meteor explosion.
-
- 2005 YY128
has been tracked by CNEOS for 17 years and its orbit has been accurately
predicted to within 100 miles.
-
- Projects
like NASA's upcoming NEO Surveyor asteroid-hunting telescope will help identify
and track these objects with greater sensitivity than before. Using infrared
sensors, the space telescope will be able to search for multiple near-Earth
objects at once.
-
- Current NEO
detection and tracking capabilities aren't quite sensitive enough to spot distant
objects, but NEO Surveyor should help remedy that, enabling NASA to detect and
catalog asteroids at much farther distances than current technologies enable.
-
- NEO
Surveyor is scheduled to launch in June 2028. For more information on
near-Earth objects and efforts to study and catalog them, visit the CNEOS
website.
-
February 15, 2023 METEOR
- likely Earth impacts? 3878
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--- Thursday, February 16, 2023 ---------------------------
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