Potentially hazardous’ asteroid the size of a BLUE WHALE will zip past Earth tomorrow at dizzying speeds of 20,512 mph, NASA reveals
- Asteroid 2015 FF could come within 2.6 million miles of Earth’s surface on Friday
- Rock has a diameter between 42 and 92 feet – up to the same size as a blue whale
- It will be travelling at 20,512 miles per hour, roughly 30 times the speed of sound
A ‘potentially hazardous’ asteroid the size of a blue whale, the largest animal on the planet, will zip past Earth tomorrow, NASA says.
The asteroid, called 2015 FF, is expected to come within 0.02864 astronomical units, or around 2.6 million miles, from the Earth’s surface, at 08:09 UTC (09:09 BST).
2015 FF has a diameter anywhere between 42 and 92 feet (13 to 28 metres) – meaning it could be the average size of a blue whale (90 feet) or almost three times as long as a London bus.
As 2015 FF flies past Earth, it will be travelling at a speed of 9.1 km per second or 20,512 miles per hour – roughly 30 times the speed of sound.
Despite being more than 10 times further out than the moon, the asteroid is classed as a near Earth object (NEO) and is being tracked by the space agency.
2015 FF is also ‘potentially hazardous’ because it comes within 0.05 astronomical units (4.65 million miles) of Earth, although it’s much smaller than other potentially hazardous objects (PHOs).
2015 FF has a diameter anywhere between 42 and 92 feet (13 to 28 metres) – meaning it could be the average size of a blue whale (90 feet) or almost three times as long as a London bus
DIFFERENT TYPES OF SPACE ROCKS
An asteroid is a large chunk of rock left over from collisions or the early Solar System. Most are located between Mars and Jupiter in the Main Belt.
A comet is a rock covered in ice, methane and other compounds. Their orbits take them much further out of the Solar System.
A meteor is what astronomers call a flash of light in the atmosphere when debris burns up.
This debris itself is known as a meteoroid. Most are so small they are vapourised in the atmosphere.
If any of this meteoroid makes it to Earth, it is called a meteorite.
Meteors, meteoroids and meteorites normally originate from asteroids and comets.
Although 2015 FF – which can be tracked on NASA’s website – is at a distance of 2.6 million miles away, this is relatively close in astronomical terms.
For this reason, 2015 FF is defined by NEO, although it’s not expected to do damage.
NEOs are an asteroid or comet whose orbit brings it into or through a zone between approximately 91 million and 121 million miles (195 million km) from the sun, meaning that it can pass within about 30 million miles (50 million km) of Earth’s orbit.
‘NEOs are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighbourhood,’ said NASA.
‘Composed mostly of water ice with embedded dust particles, comets originally formed in the cold outer planetary system while most of the rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter.
‘The scientific interest in comets and asteroids is due largely to their status as the relatively unchanged remnant debris from the solar system formation process some 4.6 billion years ago.’
At 92 feet at its very maximum, 2015 FF is actually puny compared to the largest known asteroid, Ceres, which is 580 miles in diameter (more than 3 million feet).
It’s also small compared with the 3,280-foot-wide ‘7482 (1994 PC1)’, an asteroid that made a close approach of Earth in January.
According to publicly available NASA data, there have been 29,385 NEOs discovered, as of Monday.
On average, Earth is hit by a football pitch-sized rock every 5,000 years, and a civilisation-ending asteroid every one million years, according to NASA’s Near-Earth Object Program.
In an attempt to tackle the threat of asteroids that may one day get a little too close for comfort, NASA formed a planetary defence program, that includes the Double Asteroid Redirection Test (DART) mission, that launched in November last year.
DART was launched on a SpaceX Falcon 9 rocket and will see the probe deliberately crash head first into the surface of an asteroid in October this year.
It is heading for the small moonlet asteroid Dimorphos, which orbits a larger companion asteroid called Didymos.
When it gets there it will be intentionally crashing into the asteroid to slightly change its orbit.
While neither asteroid poses a threat to Earth, DART’s kinetic impact will prove that a spacecraft can autonomously navigate to a target asteroid and kinetically impact it.
Then, using Earth-based telescopes to measure the effects of the impact on the asteroid system, the mission will enhance modelling and predictive capabilities to help better prepare for an actual asteroid threat should one ever be discovered.
The DART technique could prove useful for altering the course of an asteroid years or decades before it bears down on Earth with the potential for catastrophe.
DEFLECTING AN ASTEROID WOULD REQUIRE ‘MULTIPLE BUMPS’, STUDY SAYS
Deflecting an asteroid such as Bennu, which has a small chance of hitting Earth in about a century and a half, could require multiple small impacts from some sort of massive human-made deflection device, according to experts.
Scientists in California have been firing projectiles at meteorites to simulate the best methods of altering the course of an asteroid so that it wouldn’t hit Earth.
According to the results so far, an asteroid like Bennu that is rich in carbon could need several small bumps to charge its course.
Bennu, which is about a third of a mile wide, has a slightly greater chance of hitting Earth than previously thought, NASA revealed.
The space agency upgraded the risk of Bennu impacting Earth at some point over the next 300 years to one in 1,750.
Bennu also has a one-in-2,700 chance of hitting Earth on the afternoon of September 24, 2182, according to the NASA study.
Scientists have been seriously considering how to stop an asteroid from ever hitting Earth since the 1960s, but previous approaches have generally involved theories on how to blow the cosmic object into thousands of pieces.
The problem with this is these pieces could potentially zoom towards Earth and present almost as dangerous and humanity-threatening an issue as the original asteroid.
A more recent approach, called kinetic impact deflection (KID), involves firing something into space that more gently bumps the asteroid off course, away from Earth, while keeping it intact.
Recent KID efforts were outlined at the 84th annual meeting of the Meteoritical Society held in Chicago and led by Dr George Flynn, a physicist at State University of New York, Plattsburgh.
‘You might have to use multiple impacts,’ Dr Flynn said in conversation with The New York Times. ‘It [Bennu] may barely miss, but barely missing is enough.’
Researchers have been working at NASA’s Ames Vertical Gun Range, built in the 1960s during the Apollo era and based at Moffett Federal Airfield in California’s Silicon Valley, for the recent KID experiments.
They fired small, spherical aluminum projectiles at meteorites suspended by pieces of nylon string.
The team used 32 meteorites – which are fragments of asteroids that have fallen to Earth from space – that were mostly purchased from private dealers.
The tests have allowed them to work out at what point momentum from a human-made object fired towards an asteroid turns it into thousands of fragments, rather than knocking it off course as desired.
‘If you break it into pieces, some of those pieces may still be on a collision course with Earth,’ Dr Flynn said.
Carbonaceous chondrite (C-type) asteroids, such as Bennu, are the most common in the solar system.
They are darker than other asteroids due to the presence of carbon and are some of the most ancient objects in the solar system – dating back to its birth.
According to the findings from experiments at AVGR, the type of asteroid being targeted (and how much carbon it has in it) may dictate how much momentum would be directed at it from any human-made KID device.
From the experiments, the researchers found C-type meteorites could withstand only about one-sixth of the momentum that the other chondrites could withstand before shattering.
‘[C-type] asteroids are much more difficult to deflect without disruption than ordinary chondrite asteroids,’ the experts concluded.
‘These results indicate multiple successive impacts may be required to deflect rather than disrupt asteroids, particularly carbonaceous asteroids.’
Therefore, around 160 years in the future – when Bennu is most likely to collide with Earth, according to NASA – a KID device would have to give it a series of gentle nudges to prevent it from breaking up and sending dangerous splinter fragments flying towards Earth.
NASA’s recent study about Bennu, published in the journal Icarus, did point out there is more than a 99.9 per cent probability Bennu will not smash into Earth over the next three centuries.
‘Although the chances of it hitting Earth are very low, Bennu remains one of the two most hazardous known asteroids in our solar system, along with another asteroid called 1950 DA,’ NASA said in a statement.
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