A massive asteroid that is nearly 3 miles wide is set to make a ‘close encounter’ with Earth today.
Dubbed ‘Florence,’ the huge space rock will pass just 4.4 million miles from our planet which is about 18 times the distance between Earth and the moon.
According to NASA, this is the closest an asteroid of this size has come since it first began tracking near-Earth objects.
Star-gazers armed with just a pair of binoculars are in with a good chance of catching a glimpse of the historic event.
For astronomers, the asteroid will give them an unprecedented opportunity to study it up close through ground-based radar observations.
Nearly two thirds of NEAs (near-Earth Asteroids) have a satellite and according to Nasa if Florence does have a partner chances are we will spot it in the coming days.
‘Despite some interference from moonlight, 3122 Florence should be fairly easy to spot in even modest backyard telescopes,’ notes Kelly Beatty, a senior editor at Sky & Telescope magazine.
The best time to view will be late evening, when it’s high overhead.
Although Florence reaches peak brightness tonight it should remain nearly this bright for several days before and afterwards.
It will be gliding northward by a little less than the full moon’s diameter each hour, motion that should be obvious by watching the asteroid’s star-like pinpoint through a telescope for just a few minutes.
Florence appears this bright, despite being far away, both because it’s among the largest near-Earth asteroids and it has a fairly bright surface that reflects more than 20 per cent of the sunlight that strikes it.
In comparison, the Moon’s average reflectivity is just 12 per cent.
While it may sound alarming, NASA says asteroid Florence will safely fly past Earth at a distance of about 4.4 million miles (7 million kilometres).
It’s not the closest encounter our planet has seen with an NEO, but for this distance, the experts say it is the largest.
‘While many known asteroids have passed by closer to Earth than Florence will on September 1, all of those were estimated to be smaller,’ said Paul Chodas, manager of NASA’s Center for Near-Earth Object Studies (CNEOS) at the agency’s Jet Propulsion Laboratory.
‘Florence is the largest asteroid to pass by our planet this close since the NASA program to detect and track near-Earth asteroids began.’
The asteroid, named for Florence Nightingale, was first spotted in 1981, and the flyby in September will be the closest it’s come to Earth since 1890.
It was first discovered in Siding Spring observatory in Australia by asteroid hunter Schelte J Bus on the night of 2 March 1981 and orbits the sun once every 859 days.
And, it won’t come this close again until 2,500.
‘Lots of these Earth-approachers are only visible for a matter of hours in amateur scopes before they precipitously fade from view’, according to Bob King writing in Sky & Telescope.
Although Florence reaches peak brightness on Friday night it should remain nearly this bright for several days before and afterwards. Note that the labelled dates on this chart mark the asteroid’s location at 0:00 Universal Time (01:00 BST/ 20:00 ET the previous day). The two dark areas, labelled Chart A and Chart B, correspond to the detailed charts further down
It will be gliding northward by a little less than the full Moon’s diameter each hour, motion that should be obvious by watching the asteroid’s star-like pinpoint through a telescope for just a few minutes. Note that the labelled dates on this chart mark the asteroid’s location at 23:00 ET (04:00 BST the following day)
‘They’re just so tiny and move so fast. Not Florence. It’s neither tiny nor in a terrible hurry. Matter of fact, it’s a beast’.
‘Some of you will be able to pick it up in binoculars, and anyone with a 4-inch or larger telescope should kill it.’
The asteroid is large enough to end life as we know it if it hits, but NASA says this won’t happen this week.
A 2016 study found a 0.6-mile-wide (1km) asteroid could trigger a mini ice age if it collided with Earth.
An impact of this size would have a ‘very severe global impact’ for several years and would cause the world to become a much darker, colder and drier place, experts say.
At 2.7 miles wide (4.3km) an impact with Florence could be devastating to life as we know it.
However, it would take an asteroid around 6 miles wide (9.7km) or more to cause mass extinction, according to experts from the National Center for Atmospheric Research.
Although a collision will not be happening this year, a very small change in an asteroid’s motion – only be a few millimetres a second – can cause the asteroid to change trajectory.
While it may sound alarming, NASA says asteroid Florence will safely fly past Earth at a distance of about 4.4 million miles (7 million kilometers). It’s not the closest encounter our planet has seen with an NEO, but for this distance, the experts say it is the largest
This means that Florence could potentially pose a risk to life on Earth in years to come should its orbit change marginally.
It culminates at 13:06 BST (08:06 ET) on 1st September as it crosses between the constellations Equuleus and Delphinus.
The best places to see it pass on Friday is from Australia, New Zealand and surrounding areas as it will be night when it reaches its closest approach.
According to NASA, it will even be visible to small telescopes in late August and early September, when it brightens to the ninth magnitude
North America will get a good view at local midnight about eight hours prior to its closest approach at 08:06 ET with the next good viewing moment 16 hours after its closest approach.
For people in Europe, Friday night will be the best time to catch it – around 11 hours after its closest approach.
If people are unable to see it, the Virtual Telescope Project will be featuring a live stream of Florence starting on 31 August at 20:30 BST/ 15:30 ET.
It will take around an hour to travel a distance 2/3 the diameter of the Full Moon.
During this time, it will pass through the constellations Piscis Austrinus, Capricornus, Aquarius and Delphinus.
NASA scientists will use ground-based radar to observe its features up close, using radar imaging NASA’s Goldstone Solar System Radar in California and at the National Science Foundation’s Arecibo Observatory in Puerto Rico.
With these instruments, they will be able to see it’s true size, and even observe surface details as small as about 30 feet (10 meters).
The asteroid, named for Florence Nightingale, was first spotted in 1981, and the flyby in September will be the closest it’s come to Earth since 1890 (stock image)
Earlier this month, the space agency revealed an asteroid the size of a house set to narrowly skim the Earth in October, after it was spotted by scientists for the first time in five years.
The asteroid, dubbed 2012 TC4, first flitted past our planet in October 2012 at about double the distance of its next expected pass, before disappearing.
Now the European Space Agency (ESA) has tracked down the giant hunk of rock, which is about 15 to 30 metres (49 to 98 feet) long and roughly the size of a house.
TC4’s next approach, predicted for October 12, will bring the massive object ‘damn close’, according to experts, when it flies inside the moon’s orbit – just far out enough to miss our geostationary satellites.