May 25/26 to 29/30 Meteors

Recent video meteor rates have been very disappointing the last few nights. I’m not sure why they are so low. I’m sure the nearly Full Moon has something to do with it. Plus any dust in the air can’t be helping. Still whenever rates drop this low I start to wonder if there is a problem with my camera setup. Maybe it’s time to take a closer look and see if anything else is affecting the system.

Obs  Date(UT)      Time    TOT SPO ANT
TUS  2010-05-30   05h45m    5   5   0
TUS  2010-05-29   08h02m    5   3   2
TUS  2010-05-28   08h02m    5   5   0
TUS  2010-05-27   07h56m    6   6   0
TUS  2010-05-26   07h48m    5   2   3

TUS - Camera in Tucson operated by Carl Hergenrother
SDG - Camera in San Diego operated by Bob Lunsford
TotTime - Total amount of time each camera looked for meteors
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelion

2010 KQ is probably not an asteroid

A few days back I posted about a very small asteroid orbiting on a very Earth-like orbit. At the time the nature of the object had not been determined. It was surmised that it could be a small natural asteroid or a returning piece of man-made space hardware.

NASA’s NEO Project Office at JPL is now reporting that 2010 KQ is probably not an asteroid. That determination is based on ground-based photometry and spectroscopy by 2 telescopes in Hawaii. Richard Miles used the British Faulkes North telescope to obtain visible wavelength colors and Bobby Bus used the NASA IRTF telescope to obtain near-infrared spectra. Both observers found the object to display colors that are not common among asteroids. A similar occurrence happened back in 2002 when a newly found “asteroid” was identified as the returning S-IVB upper stage from Apollo 12. At that time Rob Whiteley and I were the first to get visible color photometry on the object. Our data showed the object to much redder than any natural solar system object. Additional IRTF data identified spectral features corresponding to organic binders in paint.

“2010 KQ” is probably a rocket upper stage that was used to launch a satellite to very high Earth orbit, the Moon or interplanetary space. Though upper stages are metallic and may or may not be painted, exposure to the solar wind will quickly redden them (a process called space weathering). The orbit of “2010 KQ” suggests the last close approach with Earth was in April 1975. There were no interplanetary launches that month. It is still possible something launched into a high Earth orbit a few years before could have stayed in a loosely bound Earth orbit until it finally leaked into orbit around the Sun in April of ’75. Two possible candidates are the German-American solar probe Helios-1 (launched on Dec 10, 1974) and the Russian lunar sample return mission Luna 23 (launched on Oct 28, 1974). As observations are made over the next few months, we will have a better understanding of when this object left the Earth-Moon system. The best source for updates on the orbit and nature of KQ is Bill Gray’s pseudo-MPEC site.

Launch cover for the Helios-1 s/c produced by Space Voyage Covers.

May 22/23/24/25 Meteors

Video meteor rates have varied by a factor of 3 over the past 3 nights. Each night was clear though the low rates on the night of May 22/23 may have been due to lots of wind-blown dust in the air. The night of May 23/24 was a late start. I was so caught up in the LOST finale that I almost forgot to turn on my camera.

With no confirmed showers active this week, most of the meteors have been sporadics with the occasional antihelion. Rates should be suppressed over the next week as the bright Moon enters the morning sky.

I changed the theme (format and background) of the blog yet again. The current theme is very similar to the previous one. Its advantages are the easy-to-use category tags at the top of the blog and increased readability.

Obs  Date(UT)      Time    TOT SPO ANT
TUS  2010-05-25   08h01m    14  13  1
TUS  2010-05-24   04h06m    9   8   1
TUS  2010-05-23   07h24m    5   4   1

TUS - Camera in Tucson operated by Carl Hergenrother
SDG - Camera in San Diego operated by Bob Lunsford
TotTime - Total amount of time each camera looked for meteors
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelion

Two Close Asteroid Fly-bys

A day or so ago I posted about a close approach by 2010 KQ, a small asteroid only about 2-6 meters across. KQ is not the only small asteroid to buzz the Earth recently. Two more asteroids, 2010 KO10 and 2010 KV39, are in the vicinity of Earth and both get much closer than 2010 KQ. Both asteroids will safely miss the Earth and don’t pose a hazard.

2010 KO10 was first seen by Rik Hill of the Catalina Sky Survey on May 20.32 UT. The 6 to 25 meter in diameter space rock passed within 112,000 miles (0.0012 AU or two-thirds of the way to the Moon) on  May 23.2 UT. At its brightest it got up to 14th magnitude, possibly putting it in visual range of very large amateur telescopes.

Orbital Parameters for 2010 KO10:
Perihelion distance = 0.920 AU
Aphelion distance = 1.032 AU
Semi-major axis = 2.984 AU
Inclination = 8.14°
Period = 2.73 years

Orbit of 2010 KO10 and the inner planets. Created with C2A. Credit: Carl Hergenrother.

.

Last night (at around May 24.37 UT) the Catalina Sky Survey (this time with Alex Gibbs as observer) picked up 2010 KV39. Tomorrow night at May 26.9 UT, 2010 KV39 will pass within 160,000 miles of Earth. Though similar in size to 2010 KO10, KV39 will only get as bright as 16th magnitude.

Orbital Parameters for 2010 KV39:
Perihelion distance = 0.714 AU
Aphelion distance = 0.958 AU
Semi-major axis = 1.203 AU
Inclination = 13.90°
Period = 0.94 years

Orbit of 2010 KV89 and the inner planets. Created with C2A. Credit: Carl Hergenrother.

Meteor Activity Outlook for May 22-28, 2010

The Meteor Activity Outlook is a weekly summary of expected meteor activity written by Robert Lunsford, Operations Manager of the American Meteor Society and contributor to this blog. The original unedited version of this week’s Meteor Activity Outlook can be found at the American Meteor Society’s site.

May is a fairly slow month for meteor activity. The Eta Aquariids are very active the first two weeks of the month then fade as the month progresses. The only other showers active this month are the weak Nu Cygnids, the Eta Lyrids, and the Antihelion radiant. These will add only 1-2 meteors per hour to the total count. Sporadic rates are low but steady as seen from the mid-northern hemisphere (45 N). Sporadic rates seen from the mid-southern hemisphere (45 S) continue to rise this month toward a maximum in July.

During this period the moon reaches its full phase on Thursday May 27th . At this time the moon lies opposite of the the sun and is in the sky the entire night. Conditions are more favorable this weekend as the waxing gibbous moon will set during the early morning hours allowing a couple hours of darkness between moonset and the start of morning twilight. The estimated total hourly rates for evening observers this week is ~1 for those in the northern hemisphere and ~2 for those south of the equator. For morning observers the estimated total hourly rates should be ~7 from the northern hemisphere and ~17 as seen from the southern hemisphere. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning May 22/23. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week:

Antihelions (ANT)

The wide Antihelion (ANT) radiant is now centered at 16h:56m (254) -23. This area of the sky lies in southern Ophiuchus some seven degrees northeast of the first magnitude star Antares (Alpha Scorpii). This radiant is best placed near 0200 local daylight time (LDT) when it lies on the meridian and is located highest in the sky. Due to the large size of this radiant, any meteor radiating from eastern Libra, northern Lupus, southern Ophiuchus, southern Serpens Cauda, western Sagittarius, or Scorpius could be a candidate for this shower. Rates at this time should be near one per hour as seen from the northern hemisphere and two per hour as seen from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of medium-slow speed.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately six sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near one per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near fifteen per hour as seen from rural observing sites and two per hour during the evening hours.

The list below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning.

Shower Name                RA     DEC   Vel     Rates
                                        km/s   NH    SH
--------------------------------------------------------
ANT Antihelions          16h 56m  -23    30     1     2
--------------------------------------------------------

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a
        dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

2010 KQ – a very small, very close asteroid

Small asteroids buzz past the Earth every day. The great majority of them pass by sight unseen. One little asteroid, now named 2010 KQ, was picked up by the Catalina Sky Survey on the night of May 16. The fact that this object is small and passing close to Earth is not unusual. Rather it’s orbit is the interesting thing about  this object.  2010 KQ has an orbit that is very Earth-like as the diagram and table below shows.

Orbit of 2010 KQ and the inner planets. Created with C2A. Credit: Carl Hergenrother.

Orbital Parameters:
Perihelion distance = 1.016 AU
Aphelion distance = 1.032 AU
Semi-major axis = 1.024 AU
Inclination = 0.07°
Period = 1.04 years

Currently the official orbit sources give 2010 KQ an absolute magnitude (H) of 28.3 which corresponds to a diameter of 3-8 meters. This H value makes a few assumptions. My independent analysis of it brightness suggests it might be smaller and fainter with an H value of 29.9. This results in smaller diameters of 2-6 meters. Either way this is a small asteroid and only a handful of smaller ones have been detected. I will be able to better define these values as more observations are made.

The very Earth-like orbit creates very slow, long Earth fly-bys. Close approach happened yesterday (May 21) at a distance of 0.0033 AU (~490,000 km or 290,000 miles). That’s just a little further than the Moon.

Small objects on similar orbits have been found in the past. Only one of these objects turned out to be a natural asteroid. All of the others were man-made space hardware. Just like on Earth where it is hard to travel anywhere without running across man-made structures or garbage, space is also littered with working and non-working satellites, rocket bodies, and assorted nuts and bolts.

Bill Gray does an excellent job of monitoring these sorts of objects and determining whether they are natural or man-made. He studies the motion of the objects along their orbits. Man-made objects are light and have a large surface area to mass ratio. This allows the solar wind and other non-gravitational forces to change the motion of the objects. Within a week or so, he should have enough data to declare the object an asteroid or just space junk. He has set up a site where you can follow the current orbit of KQ and his current thoughts on its nature.

The last time KQ was in the vicinity of Earth was back in August 1990. Prior to that it passed Earth in 1975. Perhaps it is a piece of an interplanetary or high-Earth orbit spacecraft mission launched during those times (though the 1990 date already looks unlikely).

May 16/17 – 21/22 Meteors

The past week saw the end of activity from the Halley-produced Eta Aquariids. Though there are few active showers (minor or major) for the next few weeks, background sporadic activity continues to increase as we approach the summer.

Obs  Date(UT)      Time    TOT SPO ANT ETA
TUS  2010-05-22   07h59m    6   5   1   -
TUS  2010-05-21   07h34m    14  12  1   1
TUS  2010-05-20   03h01m    10  9   0   1
TUS  2010-05-19   08h07m    10  9   1   0
TUS  2010-05-18   03h28m    11  10  0   1
TUS  2010-05-17   07h29m    7   6   1   1

TUS - Camera in Tucson operated by Carl Hergenrother
SDG - Camera in San Diego operated by Bob Lunsford
TotTime - Total amount of time each camera looked for meteors
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelions
ETA - Eta Aquariid
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