Asteroid paling berbahaya yang diketahui umat manusia tahun lalu tidak akan menabrak Bumi setidaknya selama 100 tahun

Dampak ditolak saat Badan Antariksa Eropa (ESA) meluncurkan hitungan mundur ke hari asteroid pada tahun 2052

Tepat pada waktunya untuk Hari Asteroid Sedunia: 2 April 2052, dengan peluang nyata untuk menabrak Bumi, meteorit yang terancam yang telah berada di puncak daftar bahaya global selama berbulan-bulan. Saat ini, tim kedirgantaraan Badan Antariksa Eropa sedang bekerja dengan para ahli. Spesialis di Laboratorium Eropa Selatan ([{” attribute=””>ESO) has officially removed ‘2021 QM1’ from their asteroid risk list, a result of skilled observations and analysis of the faintest asteroid ever observed with one of the most sensitive telescopes ever constructed.

With Asteroid Day Live 2022 set for June 30, we can safely say that the riskiest asteroid known to humankind in the last year will not impact the Earth – at least not for the next century.

What was it like to track this asteroid? Get the full story in ESA’s fascinating behind-the-scenes look at how European experts handle asteroid risks in the official countdown to Asteroid Day live on June 30, airing at 10:25 CEST on AsteroidDay.org and via ESA WebTV.

Impact 2052

2021 QM1 was first discovered on August 28, 2021, by the Mount Lemmon Observatory, located north of Tucson, Arizona. At the beginning, nothing stood out as unusual about the discovery – about a dozen new near-Earth asteroids are identified every dark night. Routine follow-up observations were subsequently acquired from telescopes around the globe, but these began to tell a more worrying story.

“These early observations gave us more information about the asteroid’s path, which we then projected into the future,” said Richard Moissl, ESA’s Head of Planetary Defense.

“We could see its future paths around the Sun, and in 2052 it could come dangerously close to Earth. The more the asteroid was observed, the greater that risk became.”

Perlu dicatat bahwa perhitungan orbital tunduk pada beberapa ketidakpastian berdasarkan pelacakan hanya beberapa malam, itulah sebabnya asteroid sering ditambahkan ke daftar risiko ESA segera setelah terdeteksi, dan dihapus setelah data dikumpulkan, mengurangi ketidakpastian. , Dan asteroid itu aman. Dalam hal ini, tidak mungkin.

Penjajaran kosmik yang tidak menguntungkan

Ketika bahaya tampaknya meningkat, penyelarasan kosmik yang sempurna terjadi: orbit asteroid dibawa lebih dekat ke matahari bila dilihat dari Bumi, yang tidak terlihat selama berbulan-bulan karena cahaya terang bintang induk kita.

Orbit 2021 QM1 seperti yang terlihat dari Bumi saat langit mendekati Matahari, setelah penemuannya. Kredit: ESA

“Kita harus menunggu,” jelas Marco Micheli, astronom di Pusat Koordinasi Bumi Badan Antariksa Eropa (NEOCC).

“Tetapi untuk menghentikannya, kita tahu bahwa pada tahun 2021 QM1 akan menjauh dari Bumi dalam orbitnya saat ini – yaitu, pada saat matahari terbenam, mungkin pusing tidak terdeteksi.”

Mereka bersiap-siap sambil menunggu.

Akses prioritas ke salah satu teleskop paling kuat di bumi

Observatorium Selatan Eropa Teleskop yang lebih besar (VLT) Ini sudah siap dan siap. Jika asteroid berjarak 50 meter dari matahari – dan cuaca memungkinkan – VLT ESO akan mendorong kaca 8 meternya ke dalam batu yang menghilang.

Cluster bulan yang menarik di belakang Teleskop Terbesar (VLT) ESO, Chili. Saat bulan terbenam, matahari terbit di cakrawala yang berlawanan. Teleskop terbesar (VLT) telah menutup matanya setelah pengamatan malam yang panjang, sementara operator teleskop dan astronom tertidur, sementara teknisi siang hari, insinyur dan astronom bangun untuk pekerjaan hari yang baru. Operasi di laboratorium astronomi paling makmur di dunia tidak akan berhenti. Kredit: G.Gillet / ESO

“Kami memiliki jendela sempit untuk memantau asteroid berbahaya kami,” jelas astronom ESO Oliver Hainad.

“Untuk memperburuk keadaan, itu melewati bagian dari langit[{” attribute=””>Milky Way just behind. Our small, faint, receding asteroid would have to be found against a backdrop of thousands of stars. These would turn out to be some of the trickiest asteroid observations we have ever made”.

Faintest asteroid ever observed

Over the night of May 24, ESO’s VLT took a series of new images. The data arrived and Olivier and Marco began to process them, stacking subsequent observations on top of each other and removing the background stars: it took some time.

ESO’s Very Large Telescope captures 2021 QM1 which for months topped risk lists around the globe. This pivotal sighting ruled out Earth impact in the year 2052. Over the night of May 24, the European Southern Observatory’s Very Large Telescope took a series of images of an asteroid that had topped risk lists around the globe for months. These images were some of the trickiest asteroid experts had taken, as the faint asteroid 2021 QM1 receded from view against a very starry backdrop. A series of images were processed, stacked on top of each other and stars were removed, revealing the faintest asteroid observed. Credit: ESA

The result? A positive detection of the faintest asteroid ever observed. With a magnitude of 27 on the scale used by astronomers to describe the brightness of objects in the sky, 2021 QM1 was 250 million times fainter than the faintest stars visible to the naked eye from a dark spot. (In this astronomical scale of visible magnitudes, the brighter an object appears the lower the value of its magnitude, while the brightest objects reach negative values, e.g. the Sun is magnitude -27).

Olivier was certain this small blur was in fact an asteroid, and Marco was certain that given its location, it was our asteroid.

Safe at last?

With these new observations, our risky asteroid’s path was refined, ruling out an impact in 2052, and 2021 QM1 was removed from ESA’s risk list. Another 1,377 remain.

The position of each asteroid at 12:00 CEST on June 13, 2022, is plotted. Each asteroid is a segment representing its motion over 10 days. Inner bodies move faster around the Sun (yellow circle at the center). Blue represents the inner part of the Solar System, where the Near Earth Asteroids, Mars crossers, and terrestrial planets are. The Main Belt, between Mars and Jupiter, is green. The two orange ‘clouds’ correspond to the Trojan asteroids of Jupiter. Credit: © ESA/Gaia/DPAC; CC BY-SA 3.0 IGO, Acknowledgments: P. Tanga (Observatoire de la Côte d’Azur)

More than one million asteroids have been discovered in the Solar System, almost 30 000 of which pass near Earth, with many more expected to be out there. ESA’s Planetary Defence Office, NEOCC and astronomers around the globe are looking up to keep us safe, working together to ensure we know well in advance if an asteroid is discovered on a collision course.

Watch Asteroid Day Live

How worried are the world’s asteroid experts? How did it feel to track humankind’s most risky asteroid? Get the full story in ESA’s 30-minute program counting down to Asteroid Day live on June 30, airing at 10:25 CEST on AsteroidDay.org and on ESA WebTV.

Fallen trees at Tunguska, Imperial Russia, seen in 1929, 15 km from epicenter of the aerial blast site, caused by the explosion of a meteor in 1908. Credit: Photo N. A. Setrukov, 1928

Asteroid Day is the United Nations-sanctioned day of public awareness of the risks of asteroid impacts, held annually on June 30. This year sees its return to Luxembourg for an in-person event following two years of living entirely in the virtual realm. Asteroid experts from ESA, from across Europe and worldwide will converge on the city to take part in a packed four-hour live program of panels and one-on-one interviews.