The European Space Agency (ESA) said late last week it’ll be tweeting coverage of a major international asteroid impact exercise live via social media from April 29 to May 3, 2019. You can follow the coverage via the @esaoperations Twitter channel. It’s a drill – much like the tornado drills some of us underwent in elementary school – but in this case conducted by scientists, space agencies and civil protection organizations, all acting as if an asteroid is headed for an impact with Earth. This exercise – simulating a fictional, but plausible, imminent asteroid impact – is conducted every two years by asteroid experts across the globe. It’s being conducted from the Planetary Defense Conference in Washington, D.C. ESA said:
During the week-long scenario, participants – playing roles such as ‘national government’, ‘space agency’, ‘astronomer’ and ‘civil protection office’ – don’t know how the situation will evolve from one day to the next, and must make plans based on the daily updates they are given.
You can also participate, in a more limited way, via ESA’s Facebook page. It will host two livestream videos straight from the Planetary Defense Conference. The first will be today (Sunday, April 28) at 12 UTC (14 CEST, 8 a.m. EDT; translate UTC to your time) with Rüdiger Jehn, ESA’s Head of Planetary Defense. The second will be Thursday, May 2, at around mid-afternoon European time.
For daily updates on the asteroid impact scenario, check out “Rolling coverage: Brace for hypothetical asteroid impact,” beginning on the first day of the conference, Monday, April 29.
Find out how this dramatic & risky situation will turn out LIVE from this year's #PlanetaryDefense Conference, starting Monday, 29.04. During the week, we'll post live updates the moment the experts are informed. What will they decide? #FICTIONALEVENT #ItHappenedBefore pic.twitter.com/3y7WTXlOyK
— ESA Operations (@esaoperations) April 26, 2019
This year’s hypothetical asteroid has been given the label ‘2019 PDC’. NOTE: Although realistic, all “objects” and “events” described below are completely fictional and do NOT describe an actual asteroid impact. ESA described the fictional scenario this way:
— Initial calculations suggest the orbit of 2019 PDC will bring it within 7.5 million km [4.6 million miles] of Earth’s orbit. (Or, within 0.05 AU of Earth’s orbit).
.— 2019 PDC is travelling in an eccentric orbit, extending 2.94 AU at its farthest point from the sun (in the middle of the main asteroid belt), and 0.94 AU at its closest. It completes one full orbit around the sun every 971 days (2.66 years). See its orbit in more detail here.
— The day after 2019 PDC is discovered, ESA and NASA’s impact monitoring systems identify several future dates when the asteroid could hit Earth. Both systems agree that the asteroid is most likely to strike on April 29, 2027 – more than eight years away – with a very low probability of impact of about 1 in 50,000.
— When it was first detected, asteroid 2019 PDC was about 57 million km [35.4 million miles] from Earth, equal to 0.38 astronomical units [0.38 of the average Earth-sun distance]. It was travelling about 14 km/s [8.7 miles/sec], and slowly getting brighter.
— As observations continue, the likelihood of an impact in 2027 increases. Three weeks after discovery, after observations were paused during the full moon (and reduced visibility), the chance of impact has risen to 0.4 percent – that’s a chance of 1 in 250.
— Very little is known about the asteroid’s physical properties. From its brightness, experts determine that the asteroid’s mean size could be anywhere from 100-300 meters [approximately 300 to 1,000 feet].
— Asteroid 2019 PDC continued to approach Earth for more than a month after discovery, reaching its closest point on May 13. Unfortunately, the asteroid was too far away to be detected, and it is not expected to pass close to Earth until 2027 – the year of impact.
— As astronomers continued to track 2019 PDC, the chance of impact continued to rise. By April 2019, the first day of the Planetary Defence Conference, the probability of impact will have risen to 1 in 100.
This exercise is being produced by experts from NASA’s Planetary Defense Coordination Office working together with the U.S. Federal Emergency Management Agency (FEMA) at the 2019 Planetary Defense Conference, Washington, D.C. The conference is strongly supported by ESA, NASA and other agencies, organizations and scientific institutions.
Bottom line: At the Planetary Defense Conference in Washington, D.C. – April 29 to May 3, 2019 – scientists, space agencies and civil protection organizations will be acting as if an asteroid is headed for an impact with Earth. This exercise – simulating a fictional but plausible imminent asteroid impact – is conducted every two years by these asteroid experts. This story tells how to follow the exercise on social media.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.