The Vera Rubin Observatory is poised to begin observations next year. It could detect 130 Near Earth Objects each night. Image Credit: Rubin Observatory/NSF/AURA/B. Quint
After about 10 years of construction, the Vera Rubin Observatory (VRO) is scheduled to see its first light in January 2025. Once it’s up and running, it will begin its Legacy Survey of Space and Time (LSST), a decade-long effort to photograph the entire visible sky every few nights. It’ll study dark energy and dark matter, map the Milky Way, and detect transient astronomical events and small Solar System objects like Near Earth Objects (NEOs).
New research shows the LSST will detect about 130 NEOs per night in the first year of observations.
This artist's illustration shows NASA's SPHEREx observatory in orbit. The mission will launch in 2025. Image Credit: By NASA/JPL - https://www.jpl.nasa.gov/missions/spherex, Public Domain, https://commons.wikimedia.org/w/index.php?curid=143819030
Can we secure our place in the Solar System? Not in any absolute sense because nature can be very unpredictable. But we can make the effort to safeguard our civilization by cataloguing potentially dangerous asteroids. An upcoming space telescope will help.
2022 EB5 captured by Paolo Bacci and Martina Maestripieri from at 21h 10min UT, which is 12 minutes before it entered the atmosphere, while it was only 12 300 km form Earth and its apparent speed close to 65?/sec. Credit: P. Bacci, M. Maestripieri
Last week, a small asteroid was detected just two hours before it impacted Earth’s atmosphere. Luckily, it was only about 3 meters (10 feet) wide, and the space rock, now known as 2022 EB5 likely burned up in Earth’s atmosphere near Iceland at 21:22 UTC on March 11.
While it is wonderful that astronomers can detect asteroids of that size heading towards our planet — as well as determine the asteroid’s trajectory and precisely predicted its impact location — the last-minute nature of the discovery definitely causes a pause. What if it had been bigger?
An artist's illustration of the NEO Surveyor, a space telescope designed to detect and catalogue NEOs. Image Credit: NASA/JPL
A lot of the threats humanity faces come from ourselves. If we were listing them, we’d include tribalism, greed, and the fact that we’re evolved primates, and our brains have a lot in common with animal brains. Our animalistic brains subject us to many of the same destructive emotions and impulses that animals are subject to. We wage war and become embroiled in intergenerational conflicts. There are genocides, pogroms, doomed boatloads of migrants, and horrible mashups of all three.
Isn’t humanity fun?
But not all of the threats we face are as intractable as our internal ones. Some threats are external, and we can leverage our technologies and our knowledge of nature in the struggle against them. Case in point: asteroids.
Multi-photo composite showing Perseid meteors shooting from their radiant point in the constellation Perseus. Earth crosses the orbit of comet 109P/Swift-Tuttle every year in mid-August. Debris left behind by the comet burns up as meteors when it strikes our upper atmosphere at 130,000 mph. Credit: NASA
When ‘Oumuamua was first detected on October 19th, 2017, astronomers were understandably confused about the nature of this strange object. Initially thought to be an interstellar comet, it was then designated as an interstellar asteroid. But when it picked up velocity as it departed our Solar System (a very comet-like thing to do), scientists could only scratch their heads and wonder.
After much consideration, Shmuel Bialy and Professor Abraham Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA) proposed that ‘Oumuamua could in fact be an artificial object (possibly an alien probe). In a more recent study, Amir Siraj and Prof. Loeb identified another (and much smaller) potential interstellar object, which they claim could be regularly colliding with Earth.
An artist's illustration of what Phaeton might look like up close. Credit: Heather Roper/Lunar and Planetary Laboratory
Having studies countless asteroids in near-Earth space, astronomers have come to understand that the majority of these rocks fall into one of two categories: S-type (grey) and C-type (red). These are defined by the types of materials on their surfaces, with S-type asteroids being primarily composed of silicate rock and C-type asteroids being made up of carbon materials.
However, there is also what are known as blue asteroids, which make up only a fraction of all known Near-Earth Objects (NEO). But when an international team astronomers observed the blue asteroid (3200) Phaeton during a flyby of Earth, they spotted behavior that was more consistent with a blue comet. If true, then Phaeton is of a class of objects that are so rare, they are almost unheard of.
Artist’s impression of NASA’s Double Asteroid Redirection Test (DART) spacecraft speeding toward the smaller of the two bodies in the Didymos asteroid system. Credit: NASA/Johns Hopkins University Applied Physics Laboratory
Within near-Earth space, there are over 18,000 asteroids whose orbit occasionally brings them close to Earth. Over the course of millions of years, some of these Near-Earth Objects (NEOs) – which range from a few meters to tens of kilometers in diameter – may even collide with Earth. It is for this reason that the ESA and other space agencies around the world are engaged in coordinated efforts to routinely monitor larger NEOs and track their orbits.
In addition, NASA and other space agencies have been developing counter-measures in case any of these objects stray too close to our planet in the future. One proposal is NASA’s Double Asteroid Redirection Test (DART), the world’s first spacecraft specifically designed to deflect incoming asteroids. This spacecraft recently moved into the final design and assembly phase and will launch to space in the next few years.
A computer generated handout image released by the European Space Agency shows the impact of the DART (Double Asteroid Redirection Test) projectile on the binary asteroid system (65803) Didymos. Credit: ESA/AFP
For decades, scientists have known that in near-Earth space there are thousands of comets and asteroids that periodically cross Earth’s orbit. These Near-Earth Objects (NEOs) are routinely tracked by NASA’s Center for Near Earth Object Studies (CNEOS) to make sure that none pose a risk of collision with our planet. Various programs and missions have also been proposed to divert or destroy any asteroids that might pass too closely to Earth in the future.
One such mission is the Asteroid Impact & Deflection Assessment (AIDA), a collaborative effort between NASA and the European Space Agency (ESA). Recently, the ESA announced that it would be withdrawing from this mission due to budget constraints. But this past Wednesday (Sept. 20th), during the European Planetary Science Conference in Riga, a group of international scientists urged them to reconsider.
In addition to NASA and the ESA, AIDA was designed with assistance from the Observatoire de la Côte d´Azur (OCA), and the Johns Hopkins University Applied Physics Laboratory (JHUAPL). To test possible asteroid deflection techniques, the mission intends to send a spacecraft to crash into the tiny moon of the distant asteroid named Didymos (nicknamed “Didymoon”) by 2022 to alter its trajectory.
Artist’s impression of the path DART will take to reach the asteroid Didymos. Credit: NASA
This mission would be a first for scientists, and would test the capabilities of space agencies to divert rocks away from Earth’s orbit. NASA’s contribution to this mission is known as the Double Asteroid Redirection Test (DART), the spacecraft which would be responsible for crashing into Didymoon. Plans for this spacecraft recently entered Phase B, having met with approval, but still in need of further development.
The plan was to mount DART on an already planned commercial or military launch, and would then be placed in geosynchronous orbit between December 2020 and May 2021. It would then rely on a NEXT-C ion engine to push itself beyond the Moon and reach an escape point to depart the Earth-Moon system, eventually making its way to Didymos and Didymoon.
Europe’s contribution to the mission was known as the Asteroid Impact Mission (AIM), which would involve sending a small craft close to Didymos to observe the crash and conduct research on the asteroid’s moon. Unfortunately, this aspect of the mission suffered a setback when space ministers from the ESA’s 22 member states rejected a €250 million ($300 million USD) request for funding last December.
However, during the European Planetary Science Congress – which will be taking place from September 17th to 22nd in the Latvian capital of Riga – scientists took the opportunity to advise the mission’s European partners to get back on board. As they emphasized, this mission – which is a dry-run for future asteroid redirect missions – is crucial if space agencies hope to develop the capacity to protect Earth from hazardous NEOs.
ESA’s Asteroid Impact Mission, a candidate mission due for launch in 2020, will map the smaller body of the Didymos binary asteroid system down to 1 m resolution following its arrival in 2022. Credit: ESA
Andrew Cheng from JHUAPL is the project scientist for the DART mission. As he told the AFP at the European Planetary Science Congress, “This is the kind of disaster that could be a tremendous catastrophe.” He also stressed that unlike other natural disasters, an asteroid strike “is something that the world is able to defend. We can do something.”
But before that can happen, the methods need to be further developed, tested and refined. Hence why Didymoon was selected as the target for the AIDA mission. Whereas the meteor that exploded over the Russian town of Chelyabinsk in 2013 was just 20 meters across (65 feet), but still injured 1600 people, Didymoon measures about 160 meters (525 feet) in diameter.
It is estimated that if this asteroid struck Earth, the resulting impact would be as powerful as a 400 megatonne blast. To put that in perspective, the most powerful thermonuclear device ever built – the Soviet Tsar Bomba – had a yield of 50 megatonnes. Hence, the smaller companion of this binary asteroid, if it struck Earth, would have an impact 80 times greater than the most powerful bomb ever built by humans.
In addition to advocating that the ESA remain committed to the mission, European scientists at the conference also proposed an altered, more cost-effective alternative for AIM. This alternative called for a miniaturized version of the AIM craft that would be equipped with just a camera, forgoing a lander and radars designed to probe Didymoon’s internal structure.
Simulated image of the Didymos system, derived from photometric lightcurve and radar data. Credits: Naidu et al./AIDA Workshop (2016)
According to Patrick Michel, the science lead for the AIM mission, this revised mission would cost about €210 million ($250 million USD). But as he also noted, this would require that the AIM part of the mission be delayed. While it would still conduct crucial measurements of Didymoon, it would not be part of the AIDA mission if NASA decides to stick with its original timeline.
“The main point of the mission was to measure the mass of the object, because this is how you really measure the deflection,” he said. “Two or three years (after impact), these things won’t change. Of course it’s better… that we have the two at the same time. But we found something I think that still works and allows to relax the very tight schedule.”
In the meantime, Jan Woerner – the head of the European Space Agency – indicated that the ESA would be moving forward with the new proposal when the next ministerial meeting takes place in 2019. As he told the AFP via email:
“It is important for humanity, as a species we have the means today to deflect an asteroid. We know it will happen, one day sooner or later. It’s not a question of if, but when. We have never tested asteroid deflection and there is no way we can test in (the) laboratory. We need to know if our models are correct, (whether) our simulations work as expected.”
In the end, it remains to be seen if the AIDA mission will see one or two missions traveling to Didymoon by 2022. Obviously, it would be better if both mission happened simultaneously, as the AIM mission will be capable of obtaining information DART will not. Much of that information has to do with with studying the effects of the collision up close and as they happen.
But regardless of how this mission unfolds, it is clear that space agencies from around the world are dedicated to developing techniques for protecting Earth from asteroids that pose a collision hazard. Between NASA, the ESA, and their many institutional partners and private contractors, multiple methods are being developed to divert or destroy oncoming space rocks before they hit us.
However, I’m pretty sure not one of them involves sending a bunch of miners with minimal training into space to plant a nuke inside an asteroid. That would just be silly on its face!
And be sure to check out this video that details the AIDA and Asteroid Impact Mission, courtesy of ESA:
Artist's impression of a Near-Earth Asteroid passing by Earth. Credit: ESA
Of the more than 600,000 known asteroids in our Solar System, almost 10 000 are known as Near-Earth Objects (NEOs). These are asteroids or comets whose orbits bring them close to Earth’s, and which could potentially collide with us at some point in the future. As such, monitoring these objects is a vital part of NASA’s ongoing efforts in space. One such mission is NASA’s Near-Earth Object Wide-field Survey Explorer (NEOWISE), which has been active since December 2013.
And now, after two years of study, the information gathered by the mission is being released to the public. This included, most recently, NEOWISE’s second year of survey data, which accounted for 72 previously unknown objects that orbit near to our planet. Of these, eight were classified as potentially hazardous asteroids (PHAs), based on their size and how closely their orbits approach Earth.
Artist's impression of a Near-Earth Asteroid passing by Earth. Credit: ESA
On October 6th, 2013, the Catalina Sky Survey discovered a small asteroid which was later designated as 2013 TX68. As part Apollo group this 30 meter (100 ft) rock is one of many Near-Earth Objects (NEOs) that periodically crosses Earth’s orbit and passes close to our planet. A few years ago, it did just that, flying by our planet at a safe distance of about 2 million km (1.3 million miles).
And according to NASA’s Center for NEO Studies (CNEOS) at the Jet Propulsion Laboratory, it will be passing us again in a few weeks time, specifically between March 2nd and 6th. Of course, asteroids pass Earth by on a regular basis, and there is very rarely any cause for alarm. However, there is some anxiety about 2013 TX68’s latest flyby, mainly because its distance could be subject to some serious variation.
