An Astronaut’s Perseid, A Prettier Comet Elenin And A Rare Double Conjunction

A Perseid meteor as seen from orbit in a photo taken on August 13 by NASA astronaut Ron Garan. Click to enlarge. Credit: Ron Garan/NASA

What a sight! After all these years of looking up at the Perseid meteor shower, this photo by NASA astronaut Ron Garan offers a completely new perspective. He photographed a Perseid burning up in Earth’s upper atmosphere through a window in the International Space Station and sent it to back to Earth from his Twitter account.

Judging from the clouds beneath the meteor track, few if any ground observers spotted this particular Perseid. I wonder how long he watched the shower? With never a cloud to mar the view, observing conditions must have been excellent 215 miles up. Since the station completes an orbit in about 90 minutes, if Garan sat up watching Perseids for three hours, he would have experienced two approximately 45-minute-long “nights” sandwiched between two consecutive sunrises and sunsets. Odd thought, that.

Moonlight did put a dent in Perseid meteor counts this year. On the August 13 maximum, 60-80 meteors per hour were counted by expert observers in good conditions. Sometimes that number’s 100 or more. For more details on the shower, check out the International Meteor Organization’s quicklook data page.

Eight 15-second time exposures were compiled to make this photo of Comet Elenin on August 13. Credit: Terry Lovejoy

Amateur astronomer Terry Lovejoy of Australia has been busy photographing Comet Elenin through his 8″ (20 cm) telescope even during moonlight. When I saw his most recent image today, I thought you’d enjoy seeing it, too. It’s the first that gives you a hint that Elenin is beginning to develop a nice tail. It’s faint, but you can trace it well beyond the comet’s head.

Lovejoy is hoping for even better photos once the moon is out of the way. When a bright moon is up, a time-exposure photo records moonlight along with the stars. The extra light brightens the sky and washes out faint, low contrast details. Watch for more comet pix here soon!

Early tomorrow morning Venus will be at superior conjunction on the far side of the sun from Earth. Hours later, Mercury reaches inferior conjunction between the sun and Earth. I've 'removed' the atmosphere in the map so you can see them. Created with Stellarium

A couple days ago I blogged on tomorrow’s conjunction of Venus and the sun. That’s not the only interesting planetary alignment happening this week. On the same day but later in the evening, Mercury will also be in conjunction with the sun. However, instead of behind the sun – as Venus will be – Mercury will be in in front of the sun. Venus’s conjunction is called ‘superior’ because it’s on far side of the sun from Earth; Mercury’s is ‘inferior’, because it’s on the near side.

This match-up on the same day is a relatively rare event, but don’t expect it to cause any measurable effects on Earth – the planets are simply too far away. Nor will we see Mercury and Venus with the unaided eye. They’re too close to the sun and lost in its glare. With no atmosphere to scatter light and create a bright blue sky, the moon would be a good place to view the threesome, so long as you blocked the sun with your gloved finger. This best viewing option might be the coronagraph on NASA’s Solar and Heliospheric Observatory. It’s currently showing a great view of Venus and the sun, but the field of view is a bit too small to include Mercury. Check out a recent image.

Planet lineups are quite common during any given year. In 2011, there are 22 conjunctions (lineups) among the seven planets and dwarf planet Pluto. Mercury alone lines up with Earth and the sun at inferior and superior conjunction six times this year. Since the planet orbits the sun every 88 days, that should come as no surprise.

Any gravitational effects from these planetary fun-and-games are tiny compared to the much closer moon and sun. Many are very enjoyable to watch, since we humans get a thrill seeing two bright celestial bodies near one another in the sky. The next cool pairing, or should I say ‘gathering’, happens in late October through mid-November, when Venus, Mercury and Saturn play tag in evening twilight.

25 Responses

    1. astrobob

      Doug, maybe something greater than, say, than the gravitational effect a large mountain has on your body. While both planets do exert a small pull on the Earth (and every other planet), the effect of tomorrow’s lineup versus their pull at other times of the year is too minute to matter. Strictly speaking, the amount is measurable (though not an easy task) but the effects are too small to be noticed.

  1. David

    Um how long will these planet conjunctions be going on? Lately I’ve been worrying myself over space and comets and I know its probably because I don’t understand how everything works.

    1. astrobob

      Hi David — The Venus and Mercury ones are over after tomorrow. Not to worry though. Conjunctions are very common and have been happening since the planets formed billions of years ago. The reason things line up routinely in our solar system is because all the planets, sun and moon lie in generally the same plane — kind of like a flat pancake. As we look out from Earth into the solar system, we see them occasionally “stack up” next to each other. Since they’re all in constant motion around the sun, conjunctions are brief events. Planets line up and then move apart as each orbits the sun at it own particular speed depending on distance.

  2. David

    Thank you… Um what about the comet Honda and Elenin? I’m going absolutely insane with fear and sadness. All you see online now is bad things about these comets. Like Elenin will do so much damage to earth and Honda is the first to start off the comet frenzy…. please help me understand.

    1. astrobob

      David – Comets Honda and Elenin won’t cause anything bad to happen on Earth except to inspire a small group of people to unnecessarily drum up fear about them. Read through the comments section and see my answers to some of the questions people have had about these comets. Suffice to say, they’re too small and too far away to affect events here on Earth. Comets have been flying by Earth for centuries — many each year — with not one recorded instance of one striking the Earth or any scientific evidence that they cause earthquakes and the like.

      There are all sorts of “alignments” that people see between Elenin and this or that event, but if you look closely, you’ll find hundreds (maybe thousands) of alignments every year between planets, moon, comets and asteroids (known and unknown). “Alignments” are a constant in our solar system since there are many hundreds of thousands of asteroids and a great many comets. Given that fact, we must look closer to home for the cause of things like earthquakes, tsunamis and magnetic pole wanderings. Indeed, all these events are explained by geology and the related sciences. Why the fearmongers and speculation-experts don’t give Earth and its active crust and molten core more attention is beyond me. Everyone is looking to blame comets, which are so puny and far away in comparison to the forces under our very feet. Sometimes I feel like this is what it must have been like to live in Rome circa 200 B.C. when superstition and ignorance about the workings of our planet were the norm.

      Stay cool David, this will all blow by, but be wary and skeptical of incredible claims, because once Elenin and Honda are have receded into the background, the speculators will seize on the next comet or bit of missing data to keep the anxiety dial cranked up to “high”.

    1. astrobob

      David and all — yes, Comet Honda-Mrkos-Pajdusakova passed by today. It’s now receding from Earth. As I wrote earlier, these was nothing to fear from this comet and it passed considerably closer to Earth than Elenin will — 5.6 million vs. 22 million miles.

  3. jasen

    hello astro-bob. what a cool photo! thanks for sharing. will you be taking a photo of elenin when its at is nearest point to earth? if so when will that likely to be, and will you post it here?
    thanks again, jasen 🙂

    1. astrobob

      Hey Jasen, I sure will be taking pictures during its closest approach to Earth on October 16, and I’ll post them here. Of course, the weather will have to cooperate 😉

  4. Mike


    Just found your blog about 2 months ago, loving it! Thanks for having such a fun hobby/passion and sharing it with the rest of us. I am in the process of telescope hunting. It would be my first one, had one when I was 8-10, could count on one hand how many times I used it. But after reading your blog, a life time love of the night sky, and a friends birthday gift-card (with a note that says this is for your telescope) I think it is time. Long story short, what is a good beginner scope, range $250-$150? Thank you, and keep up the observations!

    1. astrobob

      Mike, I love hearing from people who are excited to get out under the sky. Are you already familiar with finding your way through the constellations? If so, here are a couple recommendations in your price range (and a little higher): a 6-inch Dobsonian reflector at or a 5-inch equatorial reflector at
      Both are from Orion Telescopes in California. I’d lean toward the 6-inch Dob. Take a look and tell me what you think. I can suggest a couple accessories, too, like a star atlas and perhaps a “red-dot” style finder instead of the regular finderscope these scope come equipped with.

      1. Mike


        So I took a look at the telescopes you suggested and I actually am leaning more towards the equatorial reflector. The main reason is I think I would be putting the telescope in and out of my car, and possibly trying to find some remote areas to star gaze. Also, I think for my first scope $250 is my limit.

        Please tell me more about some accessories, what are the benefits of the “red-dot finder, and what are some good books. I also read an old blog of yours about a star party, which I wish to know more about haha, but you wrote about someone going through the messier group and finding/identifying them and getting some certificate. Is there a website, or book that talks more about things like that, i would like some “home work” with the scope, I think that would help me learn.

        All that to say, thank you so much for your help. I’m so excited about getting a new telescope!


        1. astrobob

          Hi Mike — equatorials are nice, but one in the $250 range might be prone to shake more than a Dobsonian. Your choice though of course. I use a regular finderscope, but many of my friends really find the ease of the “red dot” non-magnified view of the sky preferable. The field of view is wide, the view is natural and the image is normal, not flipped upside down. Of course, newer scopes often come with erect image finderscopes. Check on that option before your buy. The down side of the “red dot” is that you can only stars visible with the naked eye to find things, whereas an optical finder gathers more light and shows fainter stars.
          A good beginner’s book for objects to hunt in a small telescope is “Turn Left at Orion”. And if you want some fun observing goals, check out the Astronomical League’s observing clubs at:

  5. Edgar Luis Gomez

    On the website of Terry Lovejoy not find the picture obtained from C 2010 X1 ¿where do you find? Thanks in advance!?

    1. astrobob

      Hi Edgar, I belong to a comet observers group to which he posted a link to the image. I see you used the picture on your site.

  6. Jeremy

    Hi there a few friends and I noticed that when you go to the constellation Leo on google sky and switch to in-fared mode a large object appears. Do you happen to know what that object is? thanks Jeremy

    1. astrobob

      Jeremy, I assume that it’s a bright infrared source. It appears on both the older IRAS atlas and the recent Spitzer, so whatever it is, it’s far away and not moving.

  7. Freddy

    Hi, I have a question, what about the UFO’s that are behind Elenin? is true? is Nasa Hiding something?

    1. astrobob

      Hi Freddy, There are no UFOs behind Comet Elenin. The story is either a complete fabrication or the supposed Chinese scientist was misinterpreted or may simply be a crackpot. You can study all the recent photos of Elenin and you’ll see nothing out of the ordinary there. I’m guessing the whole thing is a rumor carried over from another rumor — the supposed UFOs behind Comet Hale-Bopp in 1997. That was also untrue.

  8. Freddy

    Thank you very much for your quick response!!
    this days I dont know what to believe, the media, internet, newspapers, they all liers…
    Once again thanks!

    1. astrobob

      You’re welcome, Freddy. All liars though? No, there’s truth out there. You just have to look around with a bit of healthy skepticism. If the claims being made are fantastic and incredible, examine them closely and find the sources. And remember Carl Sagan’s words: “Extraordinary claims require extraordinary evidence.”

  9. Freddy

    True, thank you very much, I just hope things get better here ( planet earth ) not more earthquakes, UFO’s, and all that stuff, they just talk about the armagedon, about the end of the world in 2012, I try no to pay atention you know, but sometimes you start thinking…… what if….

Comments are closed.