Near Earth Asteroid Buzz


Post 1,002 finds me pondering a near Earth asteroid. Not one of the 1,634 potentially hazardous objects currently identified and monitored by science – my thoughts are with 2015 VY105. Less than a day after discovery on November 14, VY105 passed over the Pacific Ocean at a distance of 34,000 Km. Trust me – that’s close.

Undetected until a few hours before passing, closer than many Earth orbiting satellites, traveling at an estimated speed of 62,000 km/h, we were never in danger. At 3 – 9 meters, VY105 wasn’t big enough to cause trouble. Even if it spanked our atmosphere, an asteroid that size would disintegrate before impact. Witnesses to a hypothetical demise, might have been rewarded with an outstanding fireball.

In October 2008, asteroid 2008 TC3 pulled a similar stunt. 19 hours after detection TC3 entered our atmosphere over the Sudan. Estimated at 4 meters, it vaporized long before hints of calamity. Small doesn’t necessarily mean harmless – in February 2013, a fireball and explosion over Chelyabinsk in Russia’s Ural mountains, blew out windows, injuring over 1,000 people. Undetected, this meteor wasn’t named, no impact crater was found. Science believes damage from an estimated 15 meter asteroid occurred when it exploded 15-20 Km above ground. Entering the atmosphere at a shallow 20 degree angle, it blazed across the horizon at over 62,000 km/h disintegrating at low altitude with the force of 300 kilotons TNT.

Asteroid Explodes Near Chelyabinsk, Russia on Feb. 15 2013

The asteroid that exploded near Chelyabinsk, Russia on Feb. 15, 2013 has provided scientists new insights into the risks of smaller asteroid impacts. This 3D simulation of the Chelyabinsk meteor explosion by Mark Boslough was rendered by Brad Carvey using the CTH code on Sandia National Laboratories’ Red Sky supercomputer. Andrea Carvey composited the wireframe tail. Photo by Olga Kruglova. Credit – Sandia National Laboratories.

http://www.space.com/24714-russian-meteor-blast-chelyabinsk-anniversary.html?li_source=LI&li_medium=most-popular

Rather than criticizing astronomers over a few missed space rocks – plant seeds of collective determination to properly fund science. Cosmic science encompasses far more than raising a flag on Mars. Every satellite, probe, telescope and innovation takes us closer to solving the dilemma of rogue asteroids. VY105 managed to buzz Earth hours after making itself known – we have to do better than that.

http://earthsky.org/space/asteroid-2015-vy105-buzzed-earth-this-weekend-hours-after-discovery?utm_source=EarthSky+News&utm_campaign=0e426be346-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-0e426be346-393970565

 

 

 

Blue Moon and Aquarids


Find yourself marveling at tonight’s blue moon, you could stumble upon the Delta Aquarid meteor shower. Aquarids, a lessor known spectacle to summer’s show stopping Perseids, ebb and flow from July 12- August 23. Slow and steady Aquarids prefer unobtrusive reliability to all or nothing peaks. If pushed for a peak, Aquarids would utter a reluctant disclaimer – roughly the last few days of July and early August. Unfortunately, butting heads with this years’ blue moon. Although moonlight’s pollution impacts dark sky reliability of 10-20 meteors an hour, Aquarid shouldn’t be dismissed. If you prefer the cozy comforts of home – check out NASA’s All Sky Camera site, linked below the video.

http://www.nasa.gov/connect/chat/allsky.html

For “everything you need to know about the Delta Aquarids”, another link –

http://earthsky.org/astronomy-essentials/everything-you-need-to-know-delta-aquarid-meteor-shower#when

 

Small Asteroid Hits


The Chelyabinsk asteroid over Russia on February 15, 2013 was a “small asteroid” estimated at 20 meters across. Small, yet credited with shattering windows in 7,200 buildings over 6 cities, and injuring 1,500 people.

On November 14, 2014 NASA released a map produced by the Near Earth Object (NEO) program showing 556 small asteroid atmosphere “hits” from 1994-2013. Almost all of them “burned up”, and were classified as “fireballs”. Fireballs or bright meteors are known by the term “bolide”. The map below illustrates bolide events as universal – the orange dots are day, and blue night. Size difference in dots pertain to “optical radiant energy”. I’m no scientist, and fear my explanation of the term might fall flat – the link below is helpful in that respect.

NASA announced the Asteroid Redirect Mission (ARM) in June 2014, a ambitious program aimed to identify, capture, and redirect potentially hazardous asteroids to an orbit around the Moon. See link below…

http://www.nasa.gov/content/what-is-nasa-s-asteroid-redirect-mission/#.VGxaxMlflLM

On a grander scale, all objects greater than 100 meters and orbiting or likely to orbit Earth within 100 Lunar Distance (LD) – 1 LD being the distance from Earth to the Moon, are called Potentially Hazardous Asteroids (PHA) – as of today 1512 of these objects are being monitored.

http://earthsky.org/space/heres-how-often-small-asteroids-enter-earths-atmosphere?utm_source=EarthSky+News&utm_campaign=faa7fe7c5f-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-faa7fe7c5f-393970565

 View larger | Sizes of red dots (daytime impacts) and blue dots (nighttime impacts) are proportional to the optical radiated energy of impacts measured in billions of Joules (GJ) of energy, and show the location of impacts from objects about 1 meter (3 feet) to almost 20 meters (60 feet) in size. Image credit: Planetary Science

View larger | Bolide events, 1994-2013. A bolide is what most people would call a fireball or very bright meteor. Map shows location of atmospheric impacts from small asteroids about 1 meter (3 feet) to almost 20 meters (60 feet) in size. It shows 556 separate events in a 20-year period. Orange dots indicate daytime events; blue dots indicate nighttime events. Sizes of dots are proportional to the optical radiated energy of events. Image via Planetary Science

Geminids and Gibbous Moons


When the Geminid meteor shower peaks on Dec. 13 and 14, a pesky, almost full moon is poised to steal fireball thunder. The annual Geminids are one of the most prolific night shows, with an average of 120 meteors an hour. As if losing ISON wasn’t bad enough; a bright winter moon is expected to reduce visible meteors 2 – 5 fold.

Annual meteor showers result from earth’s orbit intersecting debris from a sun orbiting comet. Radiant point, is the name given to this intersection. Debris from comet 3200 Phaethon happens to intersect our orbit in the vicinity of constellation Gemini, hence – Geminids. To find Gemini, look for the star Castor, low on the east, north-east sky around 9 PM. Castor is one of the brightest stars in the sky and along with Pollux, make up the ” twin brothers ” of Gemini. The reason Geminids produce so many visible meteors is that the constellation and radiant point swing upward; by 2 AM the point is directly above you in the sky. The angle of the radiant, translates into no poor seats for this show – you can see it from anywhere, with 2 AM as your prime time.

This year we have a waxing gibbous moon to deal with – not a deal breaker, but grounds for some new rules. Since the nearly full moon is so bright, you should wait until the moon sets. This year pre-dawn moon set offers the best view. Get out of town – away from city lights – and give yourself a few minutes to adjust to the darkness. Gibbous moon aside – I guarantee you’ll see fireballs – you don’t even have to find Gemini, the Geminids have a crazy way of appearing to come from any direction.

http://earthsky.org/astronomy-essentials/radiant-point-for-geminid-meteor-shower

To find out when the moon sets in your little corner of the world – a link…..

http://www.usno.navy.mil/USNO/astronomical-applications/data-services

Ponder the last time you wished upon a falling star.

Jupiter, Castor and Pollux rise at early-to-mid evening in early December but at dusk or nightfall  by the month's end.

Jupiter, Castor and Pollux rise at early-to-mid evening in early December but at dusk or nightfall by the month’s end.

It’s Perseid Time


Every August, Earth encounters space junk from the Swift-Tuttle Comet. The result is the Perseid meteor shower. It’s just getting started with about 10 meteors an hour. By August 12 – 13 when it reaches it’s peak, find a dark sky away from city lights to witness up to 100 meteors an hour. The best time to watch is after midnight. Scientists have dubbed this meteor shower the Perseids because the meteors streak out and away from the constellation Perseus.

This link is to National Geographic, and the photo is courtesy their site.

http://news.nationalgeographic.com/news/2009/08/090812-perseids-perseid-meteor-shower.html