2012 Lyrid Meteor Shower Meteor Profile showing peak near 04h-06h UTC

My visual meteor observing report with 30 minute (or less) intervals, and magnitude distribution

Saturday night, April 21, Mojo and I headed to our new favorite dark sky spot, Amboy Crater, one of the darkest observing locations in the US. [...]]]>

Amboy Crater at dawn

2012 Lyrid Meteor Shower Meteor Profile showing peak near 04h-06h UTC

My visual meteor observing report with 30 minute (or less) intervals, and magnitude distribution

Saturday night, April 21, Mojo and I headed to our new favorite dark sky spot, Amboy Crater, one of the darkest observing locations in the US. This spot has great horizons and its remoteness keeps all but the serious observers away, though we’ve met delightful observing buddies at this spot. Our one way drive from Monrovia, CA is 170 miles, fyi.

After a night of observing, you can’t beat the morning hike to Amboy Crater, a 6,000 year old volcanic cinder cone, either. Even in the summer it’s cool at dawn. Look carefully at the oxidized lava beds as you follow the hiking trail to the crater and you might find some Chuckwalla lizards! Chuckwallas can reach 16 inches in length, weigh up to 2 pounds and are specially adapted for desert living. Chuckwallas are my very favorite herps, well, next to the desert tortoise, that is.

The peak of the Lyrids occured at 1:30 a.m. Eastern (10:30 Pacific). The constellation Lyra was barely above my horizon at that hour. This meant the highest rates were probably recorded several time zones east of my California location. I set up my observing area, shut my eyes until about 11:00 p.m., and then I managed to observe straight through the night — from 11:40 p.m. until just before dawn at 5:16 (6:40h – 12:16h UT).

Here are a few tips I use to prepare myself for a night of meteor counting. First, I read Bob Lunsford’s weekly meteor shower recap on the Yahoo meteorobs group email list which discusses amateur meteor astronomy. It’s a good place to “lurk” and learn.

Bob wrote “The Lyrid (LYR) shower is expected to reach maximum activity on the night of April 21/22 with rates up to 15 shower members per hour. The radiant is located at 18:08 (272) +33. This area of the sky is actually located in extreme eastern Hercules, eight degrees southwest of the brilliant blue-white star Vega (Alpha Lyrae). The radiant is best placed just before the break of dawn when the radiant lies highest in the sky. While Lyrid meteors can be seen in both hemispheres, the north is favored as the radiant lies much higher in the sky. Rates will fall rapidly after maximum and little activity will be seen the remainder of the week. At 48km/sec. the Lyrids would produce meteors of medium-swift velocity. It should be noted that the Lyrids can occasionally produce bright meteors of fireball class magnitude.”

Next I familiarized myself with the spring sky and printed out some all-sky charts, marking the radiant between Lyra’s bright star Vega, and the Keystone section of Hercules. I then decided where to look — 50-70 degrees above the horizon, 20-40 degrees away from the radiant. I selected the area around the bright star Arcturus in the constellation Bootes. When counting meteors you don’t want to look directly at the radiant as the meteors will look like short streaks, or points of light.

For this shower the rates were not expected to be too high, so I decided to record (for my first time) the magnitude of each meteor. I made a note of the magnitude of Saturn, Mars and Venus and re-familiarized myself with the magnitudes of many bright stars nearby during my prep time. Then, I selected two small constellations (Corona Borealis, and the head of Draco) which contain magnitude 2-5 stars and memorized their magnitude.

Armed with all these stellar magnitudes, I settled down and waited for it to get dark. Once it did, I began the first important observation — estimating the limiting magnitude. The limiting magnitude is the magnitude of the faintest star near the zenith that the observer can detect using the slightly averted naked eye. It defines both the condition of the sky’s clarity and the quality of the observer’s eyes. I keep a set of these charts on a clipboard and take them with me on all observing trips, even if I am not observing meteors. Every 30-45 minutes, between my half-hour counting sessions, I re-counted the stars in the selected areas, to note any changes in the sky clarity or the condition of my own eyes.

In a nutshell my skies were Magnitude 6.5, which is very dark. Weather conditions: clear, 98 degrees at sunset, 62 degrees at dawn. It was a shirtsleeve weather night almost all night long, tho’ I put on a fleece jacket at about 4 a.m.

Between 11:40 p.m.and 5:16 a.m. (06:40h – 12:16h UT) I counted 36 Lyrids, 6 Sporadics and 2 Anthelion meteors. A quarter of the Lyrids I saw were very bright -1 or brighter meteors. I took short breaks between counting sessions to re-estimate the limiting magnitude, have a snack, check on what Mojo was imaging through his telescope, stargaze through my own scope, etc.

06:40h-07:10h UT – 7 Lyrids
07:30h-08:00h UT – 3 Lyrids
08:15h-08:45h UT – 5 Lyrids, 1 sporadic
08:50h-09:20h UT – 5 Lyrids, 1 sporadic
09:30h-10:00h UT – 6 Lyrids, 2 sporadics
10:05h-10:25h UT – 1 Lyrids, 1 sporadics, 1 Anthelion
Break to look at Saturn, have a snack, scan Milky Way
10:59h-11:29h UT – 2 Lyrids, 1 Anthelion
11:30h-12:00h UT – 7 Lyrids (2 fireballs!)
12:01h-12:16h UT – 1 sporadic

You can see that I saw the most meteors just as I was getting started (which was near the peak) and again near dawn (when Lyra was at its highest in the sky). Just before 5 a.m. 12h UT both Mojo and I saw a very bright bollide, greenish in color in the western sky. I estimated its magnitude at -5, brighter than Venus. It probably was much brighter. Coincidentally, 3 hours later an even more impressive bollide streaked across the California Sierra foothills, and broke up in the atmosphere, sprinkling meteorites over a wide populated area. Both of these bollides were Lyrid fireballs!

My other Meteor blogs and adventures

Flying through the Leonid Storm of 1999 – aboard USAF’s ARIA from Edwards AFB

Leonids 2002 – aboard NASA’s DC-8 from Dryden Flight Research Center

Observing meteors from the city – yes you can!

My meteor observing gear

January Quadrantids and a demoted constellation

August Perseids and meteor recording tips

Lyrid 4/22/12 fireball movie with radiant map

Mojo’s astrophotography from Lyrid shower night

Once a year the Old Town Sidewalk Astronomers pack tents and telescopes and caravan to Black Canyon Group Campground in Mojave National Preserve, an hours drive from Amboy Crater and about 3 hours from home.

Once the tents are pitched we put on a star party with assistance from the National Preserve staff, leaders of the [...]]]>

Once a year the Old Town Sidewalk Astronomers pack tents and telescopes and caravan to Black Canyon Group Campground in Mojave National Preserve, an hours drive from Amboy Crater and about 3 hours from home.

Once the tents are pitched we put on a star party with assistance from the National Preserve staff, leaders of the National Park Conservation Association and the Mojave National Preserve Conservancy plus many of their friends and members. The public is invited too, and unsuspecting nearby campers were thrilled to chance upon a starshow. Best of all, once the star party is over, we get to explore the national preserve!

On this trip (April 2010) my observing project was to see a Chuckwalla, the big pot-bellied lizard living in this desert area. We searched for them last year with members of the Southwest Herpetologists Society but didn’t see any.

Sunday after the star party, when tents & telescopes were stowed back in our cars we headed off to Amboy Crater in search of wildflowers, and hopefully, our first Chuckwalla.

Amboy Crater — well worth a trip for Geology, spring wildflowers, and lizard hunting — was formed by ash and cinders, and last erupted 10,000 years ago. The lava field terrain (43 square miles of it, actually) surrounding the crater is prime Chuckwalla territory. It’s easy to reach Amboy Crater from Barstow or Twentynine Palms, and you even get to drive on old Route 66. It is well worth a journey!

Chuckwallas can reach 16 inches in length, weigh up to 2 pounds and are specially adapted for desert living. They are strictly vegetarians and store water from plants in special glands to survive the harsh desert heat. The surrounding landscape is very salty and the Chuckwalla absorbs enough salt to kill most living things. But they have salt-removing glands in their nostrils, and as salt builds up on these glands, the lizard sneezes, and this expels the crystallized salt!

We were walking towards the crater and most everyone was way ahead of me. I was lagging behind, checking every lava outcrop for my first Chuckwalla sighting.

I stopped at one especially large outcrop, and scanned the sunny ledges. There, sunning herself, was Mrs. Chuckwalla! She was flattened against the rock to prevent airborne predators from seeing her shadow. Her round midsection was prominent, leading one herpetologist to suggest she was pregnant. I called to my hiking party who all quickly returned to see her. Soon, this poor shy girl was the subject of paparazzi!

Then Mr. Chuckwalla came out to see what the fuss was about. Male Chuckwallas have more of the red color (and black heads) and females are more tan/yellowish brown. They are majestic large lizards, and adapt their coloring to the rocks they inhabit. They’re not really fast, and need some sunshine to warm up in the morning. So, when danger approaches, they scoot into rocky crevices, puff up by gulping air, and wedge themselves into the cracks in the rock. This makes them difficult for predators to reach.

We also observed dozens of spring wildflowers on this hike and our earlier hike to Teutonia Peak, which I didn’t even write about here. Have a look at these images of our wonderful adventure, and put a Mojave spring wildflower/Chuckwalla play-date on your calendar. This is also a prime Desert Tortoise sighting location, but it was a bit windy on this weekend, and the tortoises were in their burrows.

Mojo’s amazing panoramas and additional images from both hikes are worth a look and will encourage you to put this park on your to-visit list. You will not be disappointed!