Tag Archives: Comet Honda

Comet Honda visits the ghost of comets past

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The figure of Orion with his "three in a row" belt stars stood high above the trees this morning around 5 a.m. Details: 35mm lens at f/2.8, ISO 1600 and 25 second exposure. Photo: Bob King

I really should do my winter sky observing in September. The only obstacle is having to get up before dawn. During the evening hours, we see the stars of late summer and early fall – Cassiopeia, the Summer Triangle, the Great Square of Pegasus. But as we sleep, the Earth turns and by 4 o’clock in the morning, Orion the Hunter and Gemini the Twins are high in the east and ripe for plucking with binoculars and telescope.

This stunning color photo of Comet Honda was made with a wide-field 8-inch telescope on Sept. 26 and shows the bright coma and long ion tail. Comets often have two tails: one of dust that reflects sunlight and another of gas set aglow by ultraviolet light from the sun. Click image to see a Quicktime movie of the comet showing changes in the tail. Credit: Michael Jaeger

What a sight to see Orion beneath trees still green and in temperatures well above freezing. That was the view this morning when I stumbled out to see Comet Honda-Mrkos-Pajdusakova low in the eastern sky near the start of twilight. After a peek at the Orion Nebula, I aimed the 15-inch telescope to a spot just below the bright star Regulus and bingo! Using my lowest magnification of 64x the comet was a tight, bright ball of light with the most delicate, lovely ion tail streaming away to the west. Shining at magnitude 6.5 (just below naked eye limit), Comet Honda looked like a faint star wrapped in a bit of fuzz through 8×40 binoculars. Even a 25-second exposure picked up the telltale green color of cyanogen, a glowing gas found in the comas or atmospheres of many comets.

Even this 25-second long exposure at ISO 1600 captures the green glow and short trail of Comet Honda this morning. The comet is located smack in the middle of the zodiacal light. Photo: Bob King

The comet will slowly fade over the next few weeks as it moves eastward in Leo. It passed closest to Earth back in August and is now pulling away with a current distance of about 75 million miles. For a map to help you find it, click over to this earlier blog.

The only snag to seeing the comet is its low altitude — only about 10 degrees or “one fist” high at the start of dawn 1 1/2 hours before sunrise. If you can find a place with a wide open view toward the east, you’re in business. While we may never get to see Comet Elenin post-breakup, Comet Honda makes for a solid stand-in.

In the same direction there’s a much larger phenomenon visible with the naked eye to those with dark, light-pollution free skies. Every fall when the moon has departed the morning sky, the “thumbprint” of the zodiacal (Zoh-DYE-uh-cull) light makes its appearance in the east just before the start of morning twilight for observers at mid-northern latitudes.

The weakly glowing zodiacal light reaches up from the eastern horizon along the zodical constellations this morning. Details: 18mm lens at f/2.8, ISO 1600 and 30-second exposure. Photo: Bob King

This large, oval or cone-shaped glow, which is composed of minute dust particles shed by passing comets,  spreads through plane of the solar system called the ecliptic. In fall, the ecliptic is steeply tilted upwards in the east in the wee hours of morning, “lifting” the dim, diffuse zodiacal light high enough to clear the lower, hazy air and improve its visibility.

If you’d like to see it, anytime in the next week and a half is ideal, since the moon won’t disturb the darkness required to see this curious cometary remnant. If you miss it this month, you’ll have another chance in late October. The cone is widest near the eastern horizon in Leo and narrows as you direct your gaze upward and to the right. The best way I’ve found to spot it is to turn your head left and right while facing east and look for a large, soft haze similar to but a bit fainter than the Milky Way.

It’s a fun coincidence that Comet Honda, which is shedding dust as it departs the Earth’s vicinity, is making its own contribution to the zodiacal light, ensuring that future generations of sky watchers will always have this otherworldly sight to look forward to. To learn more about it, click HERE.

The red circle shows UARS final resting place. Credit: NASA

One final news note. NASA announced yesterday that the Upper Atmosphere Research Satellite (UARS) everyone including myself was so excited about last weekend fell back to Earth at 11 p.m. Central time Sept. 23 over the South Pacific Ocean not far from American Samoa. Any debris remaining from the burn-up is probably sitting at the bottom of miles of water. No sightings of the re-entry have been reported.

Crescent moon and Comet Honda lure us out at dawn

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The crescent moon at sunrise Friday morning from Bishop, California. Credit: Andrew Kirk

Andrew Kirk’s beautiful image of the crescent moon reminds us to watch for an even thinner crescent at the start of morning twilight tomorrow. You’ll find it still in a dark sky by looking to the east an hour and half before sunrise in the constellation Leo below the star Regulus.

The lunar crescent, Comet Honda and Regulus are nearly lined up tomorrow morning low in the eastern sky. Created with Stellarium.

Almost midway between Regulus and the moon, comet 45P/Honda-Mrkos-Pajdusakova will be visible from dark sky sites with 50mm and larger binoculars as a small, dim 7th magnitude hazy patch of light. Telescopes will show it more clearly and may reveal its narrow westward-pointing tail. I’ve been trying to get out for a view, but mornings have been cloudy here. Let us know if you have success in spotting it.

OK, you try holding still for 30 seconds! A portrait of the group last night lit by a dim flashlight. (Astro B. on far right) Photo: Bob King

Last night, I had a wonderful time co-teaching a night photography class to a great group of people not worried about a little frost or put off by half  an hour of clouds before the sky finally cleared. Many took their very first time exposures of stars. As I looked at the glowing replays on their camera backs, it was a thrill to see their cool star trail and Milky Way photos. Nice work everyone!

Move over Elenin, Comet Honda’s back in town

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A series of images of the UARS satellite made with a 14-inch telescope by French astrophotographer Thierry Legault. The satellite is tumbling possibly from being hit by satellite debris in the past. Credit: Thierry Legault

First, an update on the UARS (YOU-ours). Its orbit now takes it to within 120 miles of the Earth’s surface as the satellite continues to drop hour by hour. For reference, the space station orbits about 225 miles high. NASA still doesn’t know exactly where it land, but the bus-sized bird is predicted to enter the atmosphere sometime on Friday. I’ve seen forecasts by long-time satellite watchers placing UARS’ decay possibly near New Zealand and/or Japan but to be honest, everything’s still up in the air.

Log in to Heavens Above or click HERE and enter your zip code to see if UARS will make any final  appearances over your home before its demise. Observers have reported that it’s now as bright as the brightest stars with occasional flashes as bright as Venus!

While Comet Elenin may have broken up and faded, we still wait with great anticipation to see if its remnants will show in the Solar and Heliospheric Observatory’s C3 coronagraph, a device that blocks the brilliant solar disk so astronomers can see and study the sun’s outer atmosphere. Its field of view is large enough to include background stars, the passing planets and the occasional comet that happens to swing by. Elenin will arrive at the far left edge of the view sometime on Friday and exit to the upper right around September 28-29.

Comet Honda strikes a beautiful form with a bright coma and crisp, westward-pointing tail in this photo taken this morning (Sept. 21) through a 10-inch telescope from Rome, Italy. Credit: Danilo Pivato

While Comet Elenin may be a goner, another comet that’s aroused interest this year has quietly returned to the early dawn sky. 45P/Honda-Mrkos-Pajdusakova, which we’ll abbreviate to Comet Honda, is shining at around 7th magnitude low in the east not far from the bright star Regulus. Moonlight will interfere with the view until this weekend. Find a location with a wide open view of the eastern horizon and start looking about 1 1/2 – 2 hours before sunrise. Your best bet is to locate bright Regulus and “star hop” from it to the comet.

The view facing east 1 1/2 hours before sunrise. Comet Honda will only be about 10 degrees high in a dark sky before dawn's first light. Stars are shown to about mag. 5.5. Brighter ones like Regulus, Omicron and Rho are labeled. Created with Chris Marriott's SkyMap software

Since it’s been cloudy here, I haven’t been out to see Honda yet, but the forecast looks great for the weekend, so I plan to set the alarm clock soon. While it should be visible as a small, fuzzy glow in 50mm and larger binoculars, until the moon has dwindled to a very thin crescent, you may need at least a small telescope to see the comet. Once the moon’s gone, it’ll be fair game for binoculars. The tail stands out boldly in the photo, but will appear much fainter in a telescope. Use the map above to help you locate it.

One last thing. There’s no need to be concerned over Comet Honda. It makes  regular returns to the Earth’s vicinity approximately every five years. On August 15 it passed closest to Earth at a distance of 5.6 million miles. Since then Honda’s been moving away from our planet with a current distance of 61.4 million miles. Astronomers have determined that the comet itself – the solid but friable body inside the bright coma -  measures about 1/2 mile across.

Good luck in your Honda search, and let us know what you see.

Help me Honda, help, help me Honda

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Amateur astronomer Terry Lovejoy of Australia took these photos of Comet Honda-Mrkos-Pajdusakova on August 8 (left) and August 14 through his 8-inch telescope. Because the comet was near Earth and moving quickly in the Aug. 14 photo, Lovejoy tracked it during the time exposure, causing the star images to trail.

I trust you had a reasonably good day Monday and slept well overnight. We all seem to be none the worse for wear after Comet Honda-Mrkos-Pajdusakova passed just 5.6 million miles or 23 “lunar distances” from Earth yesterday. Today it’s on its way back out toward Jupiter trekking along its orbit at approximately 12,460 miles per hour. Since Honda is a short-period comet, expect another visit in 5.3 years, the length of its orbital period.

Most of us didn’t see this comet, because it was rather faint and moving so quickly you needed a good star-charting program to stay on its tail. I myself caught it only twice, very low in the southern sky, before it slipped into the sole domain of southern hemisphere observers.

Comet Honda-M-P shines around 7th magnitude this week and appears very diffuse. Once the moon leaves the sky, sky watchers below the equator will see Honda in a dark sky, where it might be visible in 50mm or larger binoculars. Those of us on the other side of the equator in mid-northern latitudes will have to wait until about the third week of September before the comet appears in a dark sky before dawn in Leo the Lion. It’s predicted to still be around 7th magnitude and slowly fading at the time, so perhaps we’ll also see it in binoculars from a dark sky site. As mid-September approaches, I’ll provide easy-to-use directions on how to find it.

An August 6 photo of densely cratered terrain near the terminator or day-night border on Vesta. Scale of 20 km (12.4 miles) is at lower right. Dawn currently takes about 3 days to circle Vesta. Click photo to enlarge. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The Dawn probe at Vesta began its science mission on August 11, imaging the surface of the 330-mile diameter asteroid in visible and infrared light from its approximately 1,700 mile high “survey orbit”.  Dawn will also measure Vesta’s gravitational pull before spiraling down to a lower orbit at the end of August.  At that time, the craft will begin imaging the surface at much higher resolution. Click out this nice gallery of recent and older photos.

Let tonight's moon guide you to the Great Square of Pegasus. Look about one fist held at arm's length above the moon to find the Square, then continue to the left to Cassiopeia. Created with Stellarium

And now it’s time to come down to Earth. Let’s take a look at something tonight with our feet on the ground and head pointed heavenward.

The waning gibbous moon comes up in the east in the constellation Pisces the Fish during evening twilight. By 10 p.m. it’s high enough in the east to cast strong shadows and point us to the large starry asterism called the Great Square of Pegasus. The Square is the trunk or body of the mythological flying horse Pegasus and forms the most recognizable part of the constellation. Further off to the left (east) and higher in the sky, see if you can find the W of Cassiopeia.

Speedy Comet Honda to pass near Earth next week

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Comet Honda-Mrkos-Pajdusakova photographed by Australian amateur astronomer Terry Lovejoy on August 5.

It wasn’t but a week ago I was observing Comet Honda-Mrkos-Pajdusakova, which for simplicity we’ll call Comet Honda-M-P. It was very low in the southern sky in the early morning hours and a tough catch in the constellation Pisces Austrinus the Southern Fish. Using the “lure” of time, I made two observations – one around midnight and the other at 2 a.m. This way I was able to track and positively identify a faint, round hazy glow that slowly inched across the starfield over the span of two hours. Terry’s photo above captures its appearance well.

Sure wasn’t much to look at, but finding an old friend is always a pleasure. I last saw the comet back in 2001 and before that in 1995. Honda-M-P is what astronomers call a returning or periodic comet, similar to Halley’s Comet but with a much smaller orbit and hence a shorter times between returns. It was discovered by Japanese amateur astronomer Minoru Honda in 1948 and seen at nearly the same time by astronomers Antonin Mrkos  and Ludmila Pajdusakova.

Honda belongs to the short-period Jupiter family of comets or those with orbits less than 20 years under the control of the gravitational powerhouse Jupiter.  As it orbits the sun with a period of 5.3 years, it occasionally makes close passes to the planets Venus, Earth and Jupiter. When near Jupiter, the planet’s powerful gravity can alter the comet’s orbit and change its period slightly. This last occurred in 1983 and will again in 2030.

Comet Honda-M-P covers a lot of ground in the next week, plunging through the southern constellations Grus, Tucana, Hydrus and Dorado as seen from Australia. Credit: Chris Marriott's SkyMap

Next Monday August 15, Honda will pass very close to the Earth – relatively speaking – at a distance of just 5.6 million miles. To put this in perspective, that’s 23 times farther than the moon or still a long ways off. I’ve been asked if the comet will affect the Earth in any way, and the answer is ‘no’. Honda is only 0.6 miles across and far too tiny to produce any measurable effects on our much more massive planet. If anything, it’s the other way around. Earth may very slightly alter the comet’s orbit.

When I saw the Comet Honda-M-P, it was very faint in a large amateur telescope (15-inch). Today it’s brighter at magnitude 8.5 with a coma or cometary atmosphere measuring about half the size of the full moon.

If you’re worried that Earth might pass through the coma, don’t be. At Honda’s present distance of 9.3 million miles, the hazy glow around the tiny cometary nucleus is about 43,000 miles across, much too small to reach out and brush our planet. Even if we did pass through a comet’s outer coma, its effects would likely amount to a nice show of meteors at best. Comas are highly rarefied – any ice, dust or small rocks would quickly vaporize on striking the upper atmosphere.

Comet Honda-M-P animation compiled using photos taken on July 21. Click for more comet photos. Credit: Michael Mattiazzo

The closer a celestial object is to Earth, the faster it appears to move across the sky. Because the comet is closing in on minimum distance from Earth, it’s quickly picking up speed, covering more and more ground as we approach the 15th. Tonight for instance, it travels some two degrees or four times the full moon’s diameter in the southern constellation of Grus the Crane. Tomorrow that increases to three degrees, and by the 14-15th, Honda-M-P flys across some 10 degrees of sky- your clenched fist held at arm’s length – in just one night!

The next night or two, the comet will still be visible from the far southern states low in the south around 1 a.m., but by the 14th, only southern hemisphere observers will see it. To spot the comet, you’ll need at least a small telescope, since it’s very diffuse and will get no brighter than 8th magnitude. The moon will also be near or at full phase, lighting up the sky and making it even harder to find.

Two side-by-side binocular comets at dawn in Leo on October 7. Created with Chris Marriott's SkyMap

After closest approach, Honda-M-P swings back north and slowly continues to brighten, reaching 6th magnitude (naked eye limit) in late September, and finally appearing in the morning sky before dawn for northern hemisphere sky watchers in early October. It’s expected to be an easy binocular comet then, shining around 7th magnitude.

On the morning of the Oct. 7, it will be joined by Comet Elenin four degrees (eight full moons) to its north. Although both comets will be at different distances from Earth – 90 million miles for Honda-M-P and 22 million for Elenin -  they’ll lie in approximately the same line of sight. With wide-field binoculars you’ll be able to catch them both in the same field of view. What a wonderful and rare sight this will be!

Speaking of Comet Elenin, southern observers continue to observe and photograph it. It’s now magnitude 9 with a 3-4 arc minute coma and visible in 4-inch and larger telescopes. Click HERE for the latest views of the comet with the STEREO-B (behind) solar telescope.