Tag Archives: Orionids

Annual Orionid Meteor Shower Peaks This Week

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Orionid meteors appear every year around this time when Earth travels through an area of space littered with debris from Halley’s Comet. This year the peak will occur on the night of Wednesday, Oct. 21 into the morning of Thursday, Oct. 22.

“The Orionids will probably show weak activity this year,” says Bill Cooke of the NASA Meteoroid Environments Office . “Bits of comet dust hitting the atmosphere will probably give us about a dozen meteors per hour.”

The best time to look for Orionid meteors is just before sunrise on Thursday, October 22nd, when Earth encounters the densest part of Halley’s debris stream.

Observing is easy: Wake up a few hours before dawn, go outside and look up. No telescope is necessary to see Orionids shooting across the sky. Viewing conditions are favorable this year, as the light from the gibbous Moon should set by 2 a.m. EDT time, permitting good viewing just before dawn when the rates will be at their highest.

A live stream of the night sky from NASA’s Marshall Space Flight Center in Huntsville, Ala. will be available via Ustream beginning October 21, at 10 p.m. EDT. The live feed is an alternative for stargazers experiencing bad weather or light-polluted night skies. If the weather in Huntsville is clear, Orionids may be seen in the feed as early as 11:30 p.m. EDT, though the hours before dawn should show the most Orionid activity.

The display will be framed by some of the prettiest stars in the night sky. In addition to Orionids, you’ll see the Dog Star Sirius, bright winter constellations such as Orion, Gemini, and Taurus, and the planets Jupiter and Venus. Even if the shower is a dud, the rest of the sky is dynamite.

Set your alarm, brew some hot chocolate and enjoy the show!

An Orionid meteor recorded by the NASA All Sky Fireball Network station on top of Mt. Lemmon, Arizona on October 13, 2015 at 04:31 a.m. EDT.

An Orionid meteor recorded by the NASA All Sky Fireball Network station on top of Mt. Lemmon, Arizona on October 13, 2015 at 04:31 a.m. EDT.

An Orionid meteor recorded by the NASA All Sky Fireball Network station on top of Mt. Lemmon, Arizona on October 13, 2015 at 04:31 a.m. EDT.  Orionid meteors appear to come from the direction of the constellation Orion, circled in orange.

An Orionid meteor recorded by the NASA All Sky Fireball Network station on top of Mt. Lemmon, Arizona on October 13, 2015 at 04:31 a.m. EDT. Orionid meteors appear to come from the direction of the constellation Orion, circled in orange.


How Do We Know the Russian Meteor and 2012 DA14 Aren't Related?

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So how can we tell that the Russian meteor isn’t related to asteroid 2012 DA14?

One way is to look at meteor showers — the Orionids all have similar orbits to their parent comet, Halley. Similarly, the Geminids all move in orbits that closely resemble the asteroid 3200 Phaethon, which produced them. So if the Russian meteor was a fragment of 2012 DA14, it would have an orbit very similar to that of the asteroid.

It does not…



If you look at the image, the orbit of the Earth is the green circle. That of 2012 DA14 is the blue ellipse that is almost entirely within the orbit of the Earth; notice that it is close to circular. The other blue ellipse, stretching way beyond the orbit of Mars, is the first determination of the orbit of the Russian meteor. Notice that the two are nothing alike; in fact, they aren’t even close.

This is one reason — a big one — why NASA says the asteroid 2012 DA14 are not connected.

Text/image credit: NASA/MSFC/Meteroid Environment Office

One Night, Five Meteor Showers

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On the night of Oct. 15-16, NASA’s All-sky camera network saw meteors from five different meteor showers! October is known to be a busy month in the world of meteor showers, but even five is an unusually high number.


 


 The last meteor seen in the early morning skies over Huntsville, Ala., on the night of the Oct. 15-16.

 

To see videos of these meteors, and others, go to fireballs.ndc.nasa.gov and select 20111016 on the left panel. In addition to those five shower meteors, eight sporadic or background  meteors were detected. The five showers were: Delta Aurigids, or DAU, October Ursa Majorids, or OCU, Chi Taurids, or CTA, Orionids , or ORI, and Eta Geminids, or EGE. See the list at the end of this post for more information on each shower.

 

The only shower mentioned above that would be worth observing for yourself is the Orionids. The Orionids peak this Friday evening — the night of Oct. 21-22 — and are best viewed anytime after midnight. They are one of the last showers of the year that may have favorable weather to lie outside all night. If you are in Northern Alabama, October evenings are still quite pleasant for stargazing. Luckily for you the moon won’t be too much of a problem. Only a small fraction of the moon is illuminated, unlike many major meteor showers this year whose rates were considerably hampered because the light from a full moon washed them out.

 

Delta Aurigids, or DAU: Active from Sept. 20 — Oct. 16, peaking on Oct. 3 with only two meteors per hour. Velocity of 143,000 miles/hour. The Delta Aurigids are not a well-known shower thus any observations refine the information we know about them.

 

October Ursa Majorids, or OCU: Active from Oct. 12-19, peaking on Oct. 15. Velocity of 119 miles/hour. This is a very minor shower rates of less than one per hour. Radiant — where the meteors appear to come from — is in Ursa Major.

 

Chi Taurids, or CTA:  Active from Oct. 10 — Nov. 10, peaking on Nov. 3. Velocity approximately 94,000 miles/hour. This is also a shower that has very little known about it. It was recently discovered in a survey to find minor meteor showers using a meteor radar (Brown et al, 2010).

 

Orionids, or ORI: Active from Oct. 2 — Nov. 7, peaking on Oct. 21 with rates up to 25 per hour. Velocity of 150,000 miles/hour. Radiant is in the constellation Orion.

 

Eta Geminids, or EGE:  Active from Oct. 14-27.  Peaking on Oct. 18 with rates of three per hour. These are fast-moving meteors that average at 157,000 miles/hour. Eta Geminids are often confused with Orionids since their velocity and peaks are similar.

 

Brown, P., Wong, D.K., Weryk, R.J., Wiegert, P.

A meteoroid stream survey using the Canadian Meteor Orbit Radar II: Identification of minor showers using a 3D wavelet transform

Icarus 207 (2010) 66–81.

 

 

Credits: NASA/MSFC/Meteoroid Environment Office/Rhiannon Blaauw, Bill Cooke

 

Full Moon Doesn't Phase Orionids Viewing

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Despite the fullness of the moon, the all-sky meteor camera at NASA’s Marshall Space Flight Center in Huntsville, Ala., managed to detect a decent number of Orionid meteors this October — 41 in total! Thesemeteors, produced by debris from Halley’s Comet, travel at 146,000miles per hour and burn up high in the atmosphere. Most Orionids werefirst detected around an altitude of 68 miles, and completely burned upby a height between 58 and 60 miles above the ground.

Shown below are two Orionid meteors observed on Oct. 21, 2010.  The shower radiant, located near the constellation Orion, is easily visible.

 

The Orionids peaked on October 21 when the all-sky camera detected 13 double station Orionid meteors.

Images courtesy of Danielle Moser, NASA’s Meteoroid Environment Office, Marshall Space Flight Center, Huntsville, Ala.