Today, astronomers and space enthusiasts around the world collectively marvel at our erratic presence in the universe, especially as we drift through the cosmos among large asteroids like the one that wiped out the dinosaurs 66 million years ago.
June 30 is Asteroid Day, an annual holiday that reflects on the possibility of a planet-destroying space rock hitting Earth and what scientists are doing to mitigate that risk.
The day is celebrated on the anniversary of the 1908 Tunguska Event in Russia, when a space rock half the size of a football field broke into the air above a remote forest in Siberia — the largest asteroid impact ever seen on Earth. With a flash brighter than the sun, followed by a thunderous roar, the fireball killed herds of reindeer, knocked people more than 40 miles (64 kilometers) away from the impact off their porches and destroyed some 80 million trees. The impact dumped so much dust into the air that sunsets were scarlet for days and people as far away as Asia were able to read newspapers outside until midnight.
More recently, in February 2013, a 20-meter (66-foot) wide space rock slammed into Earth near the Russian city of Chelyabinsk, injuring about 1,500 people and shattering more than 3,000 windows in apartments and commercial buildings. The shock wave generated by the impact was so powerful that it circled our planet twice, scientists say.
Related: Phosphate in NASA’s OSIRIS-REx asteroid sample suggests space rock Bennu came from an ocean world
While such devastating space rocks are more likely to hit oceans than land, the 2013 asteroid impact just a decade ago “reminded us that these things do happen,” Nick Moskovitz of the Lowell Observatory in Arizona told Space.com. “Asteroids have a weird duality to them, because they’re probably the ingredients for life on Earth, but at the same time, the wrong impact in the right place can cause significant damage to the people nearby.”
Asteroid Day is a global awareness campaign led by the Asteroid Foundation in Luxembourg. Since December 2016, it has been an official day on the United Nations calendar. In previous years, the day has been celebrated with dozens of local events in institutions around the world, with lectures on asteroid science that were topical that year.
Last year for example, many events focused on NASA’s hugely successful DART missionwhich crashed a refrigerator-sized spacecraft into an asteroid called Dimorphos, knocking the space rock out of orbit by 33 minutes, most likely change the shape of the object also. DART was humanity’s first planetary defense test, proving that scientists had the technology needed to defend Earth if a similar space rock ever came on a collision course with our planet. “Last year, Asteroid Day was a lot like DART fest,” Moskovitz said. “It’s a fun day.”
This year’s celebration, taking place at around 30 institutions worldwide, including those in India, Africa, Europe and Mexico, will feature talks on Europe’s Hera mission, a follow-up to DART launching in October and designed to assess the mission’s aftermath. On Friday and Saturday (June 28 and 29) in Luxembourg, home to the Asteroid Foundation, events ranged from seminars on asteroid science and space sustainability to workshops where visitors could build spaceships out of Lego. At night, participants explored the night sky in real time by virtually controlling telescopes in Tuscany, Italy, led by astronomer Gianluca Masi, who manages the Virtual Telescope Project.
Here is a card maps locations of similar ongoing events around the world. If there aren’t any nearby, you can follow online discussions about asteroids by astronauts and industry experts who support the foundation recently aired.
Hundreds of people are expected in the U.S. today (June 30) to tour Meteor Crater with scientists. Asteroid science demonstrations and themed games are planned, and food and beverages will be available.
“Here in northern Arizona we can see the literal impact of asteroids on our planet,” said Matt Kent, president and CEO of Meteor Crater and the Barringer Space Museum, in a previous announcement“What better place to hold an Asteroid Day event than here?”
At 7 p.m. local time, visitors will head to Lowell Observatory, about a half-hour drive away, to view telescopes and hear science presentations from astronomers including Moskovitz. Because Asteroid Day falls on a weekend this year, “we could see some pretty big crowds between the two locations,” he said.
In Lowell, researcher Brian Skiff will discuss the strange quasi-moon of Venus. The space rock, also considered a near-Earth asteroid, was discovered in 2002 and recently given the snappy name Zoozve. It appears to be orbiting Venus, but is not permanently connected to the planet’s gravitational tides, meaning it will eventually be kicked away. It is considered a potentially dangerous space rock, but is not on a collision course with Earth.
Also at Lowell, Moskovitz will present a project that uses off-the-shelf security cameras to take pictures of the night sky in search of meteors, cataloging up to 500 images each night. The project, called LO-CAMS (short for Lowell Observatory Cameras for All-Sky Meteor Surveillance), “is all about cheap hardware put to good use for science,” he said. “The night sky can be very active if you have the right instruments to observe it.”
The project began eight years ago as a hobby for Moskovitz and has since grown into a full-fledged operation with dozens of cameras on the roofs of scientific institutions, schools, colleges and sometimes even private homes across Arizona. Based on the high-resolution images these cameras take, Moskovitz and the LO-CAMS team can predict the paths of pea-sized meteors and later search for pieces that may have survived their journey to the ground, “like an ultimate treasure hunt,” Moskovitz said.
In an intriguing cosmic coincidence, this year’s Asteroid Day comes on the heels of two asteroids that have just grazed Earth. Neither was on track to hit our planet, to be clear, but the encounter was notable nonetheless. The larger of the two, a Mount Everest-sized space rock called 415029 (2011 UL21), flew by our planet on Thursday (June 27), flying about 17 times farther from Earth than the moon is on average. The smaller asteroid, called 2024 MK, however, swung within the moon’s orbit of Earth on Saturday (June 29), close enough to be seen by stargazers using small telescopes in dark locations.
If an asteroid were ever to come on a collision course with Earth, asteroid-deflecting missions like DART would be crucial to reducing the risk of an impact. The mission, which is universally hailed as a success on many levels, is a testament to our current technology and the team of more than 100 scientists and engineers who developed it. However, the effectiveness of any strategy really depends on the size of the space rock and how much of a head start we can get. The only way to reduce the risk of a sudden asteroid impact is to find and track as many asteroids as possible, because the asteroids that pose a risk to Earth “tend to be objects discovered now with potential impacts tens or hundreds of years away,” Moskovitz said.
Technological advances in recent years have allowed scientists to catalog an increasing number of asteroids in our solar system, including artificial intelligence software that has previously revealed more than 27,000 asteroids overlooked in telescope imagesAt least a few million additional space rocks are expected to be discovered by the next Vera C. Rubin Observatorywhich will image the southern sky every night for at least a decade starting next year. At such a rate, the observatory is expected to double the number of known asteroids in its first six months of operation.
According to Moskovitz, scientists may be able to reduce or even largely eliminate the risk associated with large asteroid impacts in the coming decades.
“That’s a luxury the dinosaurs didn’t have, and it’s something we as a species will always benefit from.”