Scientists watched two asteroids make a “close-call” with Earth today, including one that passed by at a distance less than the distance between the Earth and the Moon.
At about 9:31am ET / 3:31am HT this morning, Asteroid 2019 OD passed the closest of the bunch, crossing the Earth’s orbit within 222,164 miles of the surface; the Moon is 238,900 miles away. The asteroid is about 393 feet wide and is chugging along in space at a mind-blowing 42,926 miles per hour. An hour later, another asteroid also traveled “close” in terms of space, nearing Earth by about 600,494 miles according to NASA.
NASA was only aware of the first asteroid coming near Earth three weeks ago. The discovery was made possible by a set of telescopes in Hawaii.
The threat of an asteroid impact on Earth is real and the government is doing more to prepare for the possibility of a future catastrophic strike. It is believed that an asteroid impact led to a massive extinction on Earth ending the era that saw dinosaurs roam freely.
In June, astronomers showed that telescopes could provide enough warning to allow people to move away from an asteroid strike on Earth. Astronomers at the University of Hawaii used the ATLAS and Pan-STARRS survey telescopes to detect a small asteroid before it entered Earth’s atmosphere on the morning of June 22. The asteroid, named 2019 MO, was 13 feet in diameter and 310,685 miles from Earth. The ATLAS facility observed it four times over 30 minutes around midnight in Hawaii.
ATLAS, which consists of two telescopes 100 miles apart on Mauna Loa on Hawaii’s Big Island and Haleakala on Maui Island, scans the entire sky every two nights for asteroids that could impact Earth. It can spot small asteroids half a day before they arrive at Earth and could point to larger asteroids days before. The Pan-STARRS telescope was also operating and captured part of the sky where the asteroid could be seen. Pan-STARRS is short for the Panoramic Survey Telescope and Rapid Response System; it too is located at the Haleakala Observatory.
While ATLAS detected the initial threat, imagery from Pan-STARRS was able to inform researchers on the entry path for that June asteroid. That particular asteroid burned-up in the atmosphere 236 miles south of San Juan, Puerto Rico; images provided by weather RADAR there confirmed the forecasts astronomers were able to make based on ATLAS and Pan-STARRS data and imagery.
ATLAS helped discover today’s near-misses and could help provide experts with additional early warning from future threats. In April, experts from NASA, FEMA, and other emergency management organizations around the country assembled for a comprehensive drill that simulated an asteroid forecast to make a direct impact in the United States.
For the last week, protestors have gathered nearby at the base of Mauna Kea to protest the construction of the Thirty Meter Telescope at its summit. Earlier this year, courts paved the way for construction to start, bringing closure to years of debate and legal battle. In June, the Governor of Hawaii announced construction would begin this summer.
Mauna Loa, where ATLAS is based, stands opposite of Mauna Kea, across the valley from which protestors have assembled. Protestors have yet to interfere with operations on Mauna Loa, which includes global CO2 monitoring for climate change studies, a weather station, and the HI-SEAS lab where scientists are simulating living and working on the Moon and Mars. Mauna Loa is the larger mountain of the two by volume, but is a very active volcano, averaging an eruption once every 8 years. Mauna Kea is not an active volcano and stands 125 feet taller than Mauna Loa, making it the best location in the United States for telescopes and astronomy.