Experts at Slooh
http://live.slooh.com/
note the asteroid is about twice the size of Trump World Tower in New York and is travelling around 29 times as fast as a high velocity rifle bullet. It is around 32 times the size of the Chelyabinsk meteor that hit Russia in 2015: "If it [2015 TB145] were to impact us, the energy released would be measured not in kilotons like the atomic bombs that ended World War Two, but in H-Bomb type megatons. It will be interesting indeed to watch Slooh track and image this substantial intruder as it passes just 300,000 miles from us."
During the broadcast, astronomer Bob Berman and guests will discuss the potential dangers posed by Near Earth Asteroids as they watch the "worrisome rock" pass our planet, while trying to work out why we only discovered it three weeks before its close encounter with Earth.
The programme on Wednesday will start at 10am EDT (1AM GMT) and
can be viewed here.
You can watch the livestream the Halloween asteroid passing Earth from 5pm GMT (2PM EDT)
here.
After four days of observations following its discovery,
the orbit of TB145 is now well known. There is no reasonable chance that it will strike either Earth or the moon. Any gravitational interactions that would cause earthquakes or epic floods can also be ruled out. Assuming typical asteroid densities and the estimated diameter of TB145, it will only have a mass that is a tiny fraction of the mass of the moon and therefore a minute gravitational impact upon either Earth or the moon.
But while TB145 will be a near miss, is it also a warning shot across Earth's bow. We know of approximately 3,300 objects that are of a similar size, classified as
Near Earth Objects, or NEOs. Given the statistics, the likelihood is that Earth will be struck by such an object on average once every
73,000 years so it's not something to be expected to occur very frequently or to lose too much sleep over. But it is a risk that must be monitored. In fact, such near misses have triggered our efforts to chart NEOs and develop
possible plans to divert them.
These plans remain in their infancy, especially given the potentially short timescales – we only discovered TB145 two weeks ago – so what would occur if an object similar to TB145 did hit Earth under similar conditions?
So what would happen?
TB145 won't hit Earth, but the following timeline of destruction outlines what might happen if something similar did. The predictions are highly speculative and are based largely on the
Chelyabinsk meteor strikeand
impact simulators by Imperial College London.
Around two weeks before impact, a 300m asteroid, similar in composition to a burnt-up comet is discovered. Later observations support orbital parameters and confirm an impact.
Ten days later, observations reveal that the impactor is actually a loose composition of three
similarly-sized objects. Consequently, three impacts are expected and the coast of eastern Australia is estimated to be the most likely location for the strike. Additionally, the timings of the impacts can be predicted to a few minutes' precision. A strike into water appears to be the most likely outcome, triggering a tsunami, so coastal areas are evacuated.
Just days after the evacuation, the objects enter the Earth's atmosphere. They create a gigantic trio of smoke trails as they start to burn up in the high atmosphere with an entry speed of 30km/s – or 108,000 km/h. After about three to five seconds, two of the objects detonate as air blasts at an altitude of 20km creating a bright flare. The trails race across the skies of
southern Queensland and, about seven seconds after they entered the atmosphere, the third object reaches ground level and detonates in open water.
A 5m megaton explosion
The impact releases 5m megatons of energy, as well as a sea quake of about 7 on the Richter scale. It triggers a tsunami 50km off the east coast of Australia.
Around a minute after the objects entered the atmosphere, observers located under the two air blasts hear and feel the devastating shock waves.
The explosion flattens trees and small buildings, scorching the area directly under the blast and causes considerable loss of life within the two affected 20km diameter zones. Luckily, both blast zones miss denser populated areas such as Brisbane.
Five minutes after the impact, a tsunami wave between
five and 15 metres in height hits the first coastal regions of Australia's east coast, causing considerable damage and loss of life. It now races inland but quickly dissipates – although the wave will continue to travel and cause damage in less well-prepared or equipped regions of the Pacific.
Over the last seven minutes, debris from the first two objects destroyed during the air blast will have rained down upon an area approximately 50km wide. The debris varies in mass, some causing further damage to property.
The end of it all?
Overall, no lasting global damage would be caused by such an event. But on a local level, it would impact economies severely, potentially causing large loss of life. The tsunami alone could be devastating.
A hypothetical event such as this shows that an object such as TB145 would not wipe out humanity or cause widespread global damage. But it also shows that countries will need to continue to work together to address the possible dangers of asteroids and develop effective methods of deflection.
It is not productive
to feel threatened by asteroids on a daily basis. Crossing the road can be far more dangerous. Indeed, TB145's fly-by will give us a unique insight into an asteroid that might be a retired comet. Space offers us far more insight and wonder than doom and despair.
But it always pays to keep an eye out, for the bad and the good.
Daniel Brown, Lecturer in Astronomy,
Nottingham Trent University
This article was originally published on
The Conversation. Read the
original article.
I wouldnt care if we all went up in a big puff of smoke TBH
Not it but a pretty one.
