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4660 Nereus, asteroid the size of the Eiffel Tower, to fly past Earth

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Wildfire Camera Captures Launch of NASA’s Asteroid-Deflection Mission

The launch of a SpaceX rocket taking a NASA spacecraft to an asteroid was captured by a wildfire camera on November 23, with the bright flash briefly lighting up the nighttime footage.(Credit: ALERTWildfire via Storyful)

An asteroid roughly the size of the Eiffel Tower will fly past Earth on Saturday morning, coming within 2.4 million miles of our planet — which is considered close in cosmic terms.

The 4660 Nereus is 1,083 feet in diameter and is the shape of an egg, according to EarthSky, which offers night sky and science news. Its size is often compared to the Eiffel Tower in Paris, France.

It’ll come closest to Earth at approximately 10:51 a.m. ET but still be about 10 times farther away than the moon, the outlet reports.

The asteroid is classified as a “Potentially Hazardous Object,” but that doesn’t mean that it is on course to collide with Earth. NASA defines this classification as a near-Earth object whose orbit brings it within 4.7 million miles of Earth’s orbit and is greater than 500 feet in size.

The 4660 Nereus was discovered in 1982 by Dr. Eleanor Helin, an astronomer who pioneered the search and survey of near-Earth asteroids.

Nereus makes close approaches to Earth several times each century, according to EarthSky. This, coupled with the fact that it’s a relatively “slow” asteroid traveling at roughly 14,719 mph, means that it has been considered an ideal asteroid to visit. Research back in 2009 called it “a prime space mission target.”

Asterank, a scientific and economic database of more than 600,000 asteroids, estimates that Nereus’ value is at $4.71 billion in precious metals. 

FILE IMAGE – Asteroid 243 Ida, discovered by the Galileo probe in 1993, is pictured in an illustration. (Photo by: QAI Publishing/Universal Images Group via Getty Images)

NASA has invested in technology concepts aimed at mining asteroids and lunar craters. In October of 2020, its spacecraft descended to an asteroid and momentarily touched the surface to collect a handful of cosmic rubble for return to Earth.

It was a first for the U.S. and only Japan has scored asteroid samples, according to the Associated Press.

On Sunday, 2021’s best and brightest comet — known as Comet Leonard — will also make its closest approach to Earth, coming within 21 million miles of our planet, EarthSky reports. It will be visible in the skies of both the Northern and Southern hemispheres this month with a pair of binoculars, according to the outlet.

Comets and asteroids are both leftovers from the formation of our solar system and orbit the Sun similar to how Earth does, but comets are icier and develop tails as they approach the sun, NASA says.

RELATED: NASA DART mission: Spacecraft to deliberately crash into asteroid’s moon

This story was reported from Cincinnati.

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Science

$5-billion asteroid Nereus flies by tomorrow

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Nereus is approximately 330 meters (yards) wide. Its size is often compared to the Eiffel Tower. Image via NASA.

A 1,083-foot (330-meter) asteroid has created a buzz on social media this week. It’ll pass Earth on Saturday, December 11, 2021. Closest approach will happen at 13:51 UTC (10:51 a.m. EST; translate UTC to your time) on December 11. It will not strike Earth. At its closest, Nereus will pass about 2.4 million miles (3.9 million km) away. That’s close on a cosmic distance scale. But it’s still about 10 times the moon’s distance. Yet this close pass and others has caused 4660 Nereus to be classified as a Potentially Hazardous Asteroid. It makes close approaches several times each century. And – in part because it comes close and in part because it’s “slow” – space entrepreneurs have cast their gaze toward Nereus as well. By some reports, the space rock is worth an estimated $5 billion in precious metals.

Nereus completes an orbit around the sun every 661 days (1.81 Earth-years). Saturday’s close pass of 10 lunar-distances will be its closest until 2060, when Nereus will pass at only three lunar-distances.

Will you see it?

This object will not be visible to eye alone. Asteroid 4660 Nereus will reach a visual magnitude around 12. That’s far too faint to see with the eye. To see Nereus, you would need at least an 8-inch (20-cm) telescope, or larger.

An amateur astronomer pointing a telescope at the correct location and time, can carefully observe the stars in the field of view, and then compare the view 15 or 20 minutes later to try to detect an apparent star that has changed position. The moving “star” will be asteroid Nereus. A long-exposure image would be an easier way to detect the space rock, since it will appear as a streak or line, because of its motion.

On December 9, 2021 at 9:00 p.m. CT, asteroid Nereus will be located close to star HIP 52064. Illustration by Eddie Irizarry / Stellarium

Video of asteroid Nereus

Astronomer Alessandro Marchini emailed EarthSky to say that his group at the University of Siena spent some time this week observing asteroid 4660 Nereus. He called it “a very interesting object” and said:

Asteroids are one of the research fields of our observatory: analyzing their changes in brightness over time, we can estimate their shape and their rotation period.

I made a time-lapse video with the images collected with our telescope in more than 3 hours on December 7, with the rush among the stars of the asteroid Nereus.

You can see Alessandro’s video below:

Space entrepreneurs are eyeing it

Asteroid Nereus is an elongated rock that travels at 14,719 miles per hour (23,688 km/h). While this may sound like a huge speed, Nereus is in fact a “slow” space rock compared to many other asteroids. That relatively low speed is an advantage for those who want send a robotic spacecraft in the future to study it. That is, its slow speed means a spacecraft can rendezvous with the asteroid more easily. In 2009, space scientists considered Nereus “a strong candidate for a rendezvous mission.” It would take about a year for a robotic spacecraft to enter orbit around Nereus.

And space entrepreneurs are eyeing Nereus as well, for the same reason, because of its slow speed relative to other asteroids. The Hill reported on December 1:

Asterank, a database that monitors more than 600,000 asteroids, estimates that Nereus’ value is at $4.71 billion, making it one of the most cost-effective asteroids to leverage for mineral resources. The asteroid is thought to contain billions worth of nickel, iron and cobalt.

Asteroid mining is a concept that began to gain popularity in the early 2010s, but now as the commercial space industry has taken off with big players like Blue Origin and SpaceX, it could pick back up again starting with Nereus.

View larger. | Lots of asteroids – indeed, perhaps most of the millions of asteroids in our solar system – are valuable because of the metals they contain. But Nereus’ slow speed makes it a logical first target. Chart via Asterank

EarthSky 2022 lunar calendars now available! They make great gifts. Order now. Going fast!

Astronomers are studying it, too

In 2002, the space rock made a similar approach to Earth which enabled scientists to study its shape and size using radar. Using the Arecibo Observatory and the Goldstone Antenna at California, astronomers sent radio signals that allowed them to obtain very good radar images. However, since this week’s approach is slightly closer than the previous ones, scientists might detect some surface features that were not visible in 2002.

This closer approach might also reveal if the asteroid has a “moon” orbiting around it, as many asteroids do. Bad luck, though. Astronomers say the iconic Arecibo Observatory in Puerto Rico was the best tool for detecting a “moon” or secondary space rock. And, as you might have heard, Arecibo collapse and was decommissioned last year.

But astronomers are already studying asteroid Nereus during this flyby, with other earthly observing tools. Radar observations from Goldstone started on December 5. They’re expected to continue for about two weeks.

This is a radar image of asteroid 4660 Nereus. If you saw the asteroid through a small telescope it would look, true to its name, “star-like.” Image via NASA/NSF/Arecibo Observatory.
Orbit of Asteroid 4660 Nereus via NASA/JPL.

Bottom line: Asteroid Nereus will pass Earth at about 10 lunar distances (2.4 million miles, 3.9 million km) on Saturday, December 11, 2021.

Eddie Irizarry

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About the Author:

Eddie Irizarry of the Sociedad de Astronomía del Caribe (Astronomical Society of the Caribbean) has been a NASA Solar System Ambassador since 2004. He loves public outreach and has published multiple astronomy articles for EarthSky, as well as for newspapers in Puerto Rico. He has also offered dozens of conferences related to asteroids and comets at the Arecibo Observatory.
Asteroid 33012EddieIrizarry, a 7.8 km space rock, has been named in his honor.

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Science

What You Really Need to Know About That Asteroid Flying ‘Towards’ Earth Next Week

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A larger-than-usual asteroid is due to make a flying visit past Earth next week, on December 11.

It’s called 4660 Nereus, a relatively frequent visitor to near-Earth space, which means it’s been well characterized, with a diameter of 330 meters (1,083 feet). That’s a little bit smaller than the height of the Empire State Building.

 

Despite the sensationalized tabloid headlines, 4660 Nereus is going to skim by at a nice, safe distance of 3.93 million kilometers (2.44 million miles) – just over 10 times the distance between Earth and the Moon.

Because of its size and distance from Earth, 4660 Nereus is classified as a potentially hazardous object. That classification includes any asteroid that will pass within 7.48 million kilometers (4.65 million miles) of Earth’s orbit, and is larger than about 140 meters (500 feet) across. There are a lot of rocks that fall into that category.

There are many reasons for tracking them. These include making sure that they haven’t deviated off their known orbits onto a trajectory more dangerous to Earth, and keeping an eye on groups of asteroids to maintain an awareness of what’s moving through near-Earth space.

4660 Nereus, first discovered in 1982, is special – not because it is dangerous, but because it flies by Earth with relative frequency. Its 1.82-year orbit around the Sun brings it near to us roughly every 10 years or so, although although in space terms ‘near’ is still ‘a safe distance away’.

Because of this, the asteroid has been considered a target for asteroid missions, such as Hayabusa (which ultimately visited Itokawa instead).

 

Its close approach next week will be the closest 4660 Nereus will be in decades. Its next close visit will be on 14 February 2060, when it will fly by at a distance of approximately 1.2 million kilometers (over three times the distance between Earth and the Moon).

While the asteroid poses no threat, it’s better to be prepared than not, since we know asteroids have significantly affected Earth in the past.

Space agencies are working on that. Just last week, a NASA spacecraft launched on a mission called the Double Asteroid Redirection Test or DART, to try and ram an asteroid to knock it off-course. That encounter is due to take place in September of next year.

So you can rest easy that, of all the things you have to worry about, asteroids landing on your head is not currently one of them. And if you’re really worried, you can keep an eye on upcoming asteroid close approaches here and here.

 

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