Remember last month when NASA issued press releases and put spokespersons in front of the media to “assure” us that no asteroids would hit the Earth between September 15th and September 28, 2015? Well, a huge asteroid is heading this way with an estimated day of arrival on Halloween (October 31st) and NASA is only “predicting” it will not hit Earth. Is this a poor choice of words or is NASA hiding something?
According to NASA’s report, asteroid 2015 TB145 was just discovered on October 10th, 2015. It's predicted to approach the Earth within 1.3 Lunar distances or about 490,000 km (305,000 miles) on October 31st, 2015, at about 17:00 UT (7 am EDT). The diameter is between 950 and 2,130 feet (290 to 650 meters). That doesn’t sound too big, does it?
Then it gets worse. The asteroid is nicknamed Spooky (because of its Halloween arrival or something else?) and its orbit is described as “an extremely eccentric and a high inclination orbit.” The encounter velocity is expected to be 78,290 miles per hour, which is considered to be unusually high. Its Tisserand parameter – a way of determining size - is 2.937 which puts it close to comet size. Spooky!
Then there’s this. When asteroid 2015 TB145 was discovered on October 10th, NASA gave it a 9 on the Torino Impact Hazard Scale. Here’s what that means:
A collision is certain, capable of causing unprecedented regional devastation for a land impact or the threat of a major tsunami for an ocean impact. Such events occur on average between once per 10,000 years and once per 100,000 years.
SPOOKY! On October 22nd, this was reduced to Code 8. Before you breathe that sigh of relief, here’s what an 8 means:
A collision is certain, capable of causing localized destruction for an impact over land or possibly a tsunami if close offshore. Such events occur on average between once per 50 years and once per several 1000 years.
Still spooky! An asteroid of this size would do major damage on impact. Is NASA telling employees to head for their disaster shelters?
The flyby presents a truly outstanding scientific opportunity to study the physical properties of this object.
So it sounds like NASA likes the odds on its “prediction” of a near miss.Where will you be on Halloween? Trick-or-treating? Peering into your telescope? Shaking under a table in your basement table mumbling "Curse you, Spooky!"?