In the Sky This Month – July 2010

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of July 2010.

July 2010 Highlights

* Total Solar Eclipse on the 11th for the South Pacific
* Venus, Mars and Saturn close in on each other in the evening sky
* Venus passes within 2° of bright star Regulus on the 8th
* Mars and Saturn within 1.8° of each other on the 30th
* Mercury has a mediocre evening apparition in July/August (great from SH)
* Mercury passes within 0.3° of Regulus on the 27th
* Comet 10P/Tempel 2 reaches small telescope brightness in the morning sky

Note: If anyone has pictures or observations of these objects/events and want to share them, send me a comment and I’ll post them on the blog.

Planets

Venus – Venus is the brightest “star” visible in the early evening (at magnitude -4.2). Low in the west it sets about 2 hours after the Sun. Maximum height above the horizon was reached over a month ago. As a result, Venus will appear to sink lower in the sky every night. Still, it will be well placed for easy observing for the next 2 months. If you are located south of the equator, this is a great apparition and Venus will continue to climb higher till late August. Regardless, of where you are located it will be hard to miss brilliant -4 magnitude Venus in the west an hour or 2 after sunset.

July 10 - Venus within 1.0° of bright star Regulus
July 14 - Moon passes within 5.5° of Venus

Mars – Mars moves rapidly from the constellation of Leo and into Virgo this month. Though fading from magnitude +1.3 to +1.5 it is still an obvious red beacon in the southwest right after sundown. It’s brightness is comparable to that of the other bright stars. Mars starts the month 23° from Venus and 15° from Saturn. By the end of the month, Mars will have caught up to Saturn. Venus isn’t far behind and all three planets will share the same part of the sky in August.

July 16 - Moon passes within 5.6° of Mars
July 30 - Mars and Saturn within 1.8° of each other

Saturn – This month Saturn is located in Virgo and visible in the southwest during the early evening hours. At magnitude +1.1 it is slightly brighter than Mars. The two will be within 2° of each other at the end of the month. Telescope users should note that Saturn’s rings are still within a few degrees of edge-on.

July 16 - Moon passes within 7.4° of Saturn
July 30 - Saturn and Mars within 1.8° of each other

Jupiter Jupiter once again returns to sight as a brilliant star in the east-southeast before dawn. The magnitude -2.6 planet will get brighter and better place for observing over the next few months. Last year Jupiter made a series of close approaches to Neptune. This year Jupiter will do the same for Uranus. All month long Jupiter will be located within 2-3° of Uranus.

July 3 - Moon passes within 6.5° of Jupiter
July 31 - Moon passes within 6.6° of Jupiter

Mercury – Mercury will start the month too close to the Sun for observation. By mid-month, it starts to peak above the western horizon after sundown.  The apparition is a great one for southern hemisphere observers but a so-so one for northern observers. The

July 12 - Moon passes within 3.9° of Mercury
July 27 - Mercury passes within 0.3° of bright star Regulus

Meteors

Meteor activity should really pick up in July. The year is usually split in 2 with January through June having low rates with few major showers while July through December (really through the 1st week of January) have high rates with many major showers.

Sporadic Meteors

Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During JuLy, 10-16 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

No major showers are active this month.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Starting this month, info on most of the minor showers will be provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.

Additional information on these showers and other minor showers not included here can be found at the following sites: Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2010 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

Comet 10P/Tempel 2

’10P’ says it all. This was only the 10th comet to be observed at a 2nd apparition meaning we’ve been following this comet for a long time. Discovered by prolific German comet discoverer Ernst Wilhelm Leberecht Tempel in Marseille, France on July 4, 1873, Tempel 2 has been observed at nearly every return since then. The comet’s current orbit brings it to within 1.42 AU of the Sun on July 4 and to within 0.65 AU of Earth in late August.

The comet is currently at a brightness of 9.0 to 9.5 magnitude and should brighten by another half magnitude this month. This is a large diffuse object so it will be more difficult to see than your average 9th magnitude comet or deep sky object. From my moderately light polluted backyard and 12″ telescope, the comet was a difficult object and was estimated to be magnitude 10.0. From a dark site and 30×125 binoculars, the comet was much brighter (magnitude 9.5), larger and easier to see. The added brightness was probably due to the dark site allowing me to see much more of the comet’s coma.

Tempel 2 is a morning object moving from the constellation of Aquarius to Cetus.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Comet C/2009 K5 (McNaught)

If you are looking for Comet C/2009 R1 (McNaught), which was a nice bright naked eye comet last month, this Comet McNaught isn’t the comet you’re looking for. C/2009 R1 is now too close to the Sun to be seen. The lesser known, and fainter but more observable, ‘Comet McNaught’  is Comet C/2009 K5 (McNaught). This will probably be the last month to catch a glimpse of this comet in backyard telescopes.

With perihelion back on April 30 of this year at a distance of 1.42 AU from the Sun, C/2009 K5 may still be bright enough to be seen in small backyard telescopes from dark sites. At mid-month it will be located 1.78 AU from the Sun and 2.47 AU from Earth.

Observations over the past month show the comet to be around magnitude 8.5. With the comet in full retreat from the Sun and Earth, it should fade rapidly from here on out. The comet will start the month between 8.5 and 9.0 but should fade to fainter than 10.0 by the end of the month. Due to its located in the northern constellations of Camelopardalis and Lynx, the comet can be seen at all hours of the night from high northern latitudes. It is best in the evening right after the end of twilight.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Asteroids

Binocular and Small Telescope Asteroids (V < 9.0)

(1) Ceres

Ceres is the biggest asteroid in the Main Belt with a diameter of 585 miles or 975 km. It is so big that it is now considered a Dwarf Planet. Classified as a carbonaceous (carbon-rich) Cg-type asteroid, there are suggestions that it may be rich in volatile material such as water. Some even propose that an ocean exists below its surface. Ceres is the other target of NASA’s Dawn spacecraft which is scheduled to visit it in 2015.

This month Ceres will be at opposition and brightest. The asteroid will start the month at magnitude 7.4 and fade to magnitude 8.1 by the end of the month. All month long it will be retrograding on the border of Sagittarius and Ophiuchus.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Ceres from Heavens Above.

About Carl Hergenrother
I am a professional astronomer specializing in the study of comets, asteroids and meteors. This blog will focus on my professional and amateur work in this field

15 Responses to In the Sky This Month – July 2010

  1. ibrahim says:

    June 5 2010 i looked out of my window at 3:57am and i only saw one star from its view but the star was flashing and flickering it would dim and get brighter. It did this for some time showed i be conserned

  2. Lu says:

    There is a very bright star/planet in the sky tonight (the am of 10th of july)- i think toward the northeast horizon, and i spotted it at 1 am in the morning… could it be venus, or would that have set by then?

    Thank you,
    Lu

    • Matt says:

      1 am in the morning? that would have to be jupiter then… Have a look at it through binoculars and you should be able to tell. even better take a look through a telescope. Jupiter is great to look at.

  3. german says:

    Has anyone seen a bright light object flying west to east between 9:30pm and 11:00pm? I have observed it for two and half week already. It looks like a star and fly about 2 to 3 thousand feet high. On some nights remains bright until gone on the eastern sky. Some other times the light deems out and the object is no longer visible. Sometimes speeds vary. Last night it took longer to pass by and almost came to a complete stop right above the house. No sound and or any other lights (green, red) visible. I have video tape it and look at it thru biconulars. I can’t make a shape since the bright light is so powerful. Any Ideas what this object could be?

  4. Maris says:

    July 12 approx. 10pm I was driving near downtown Meriden, CT and saw fire in the sky. The fire was a significant size (so I knew it wasn’t fireworks or a lantern, etc.) the way it burned looked a lot light a hot air balloon so I went to a dark street where I could see it better. It was traveling slower than a plane and when I stopped to get a clearer look, there was no balloon, just this fire burning from a central point. I watched it for several minutes as it traveled north toward hartford, but then it was suddenly gone. Any ideas what it could have been?

    • Carissa says:

      It could have been a flare from a flare gun. Your description sounds just like a flare since they hang up in the sky for a while and very slowly fall down until it vanishes.

  5. Matt says:

    I have a question for anyone that will read.
    5:59 am (AEST) this morning, 19th July, I saw a bright light (bright enough to be mercury. Maybe around mag -2/-3) moving very rapidly across the Northern sky. I cannot find anywhere what it could’ve been.
    Does anyone know what it could’ve been?

    Thanks,
    Matt

  6. Dennis says:

    Just saw the biggest meteor I have ever witnessed. I am in the Coachella Valley, looking outside my window to the southwest. Large ball of white light with small trail, moving towards the south. Was about 30 degrees above horizon. Occured at 9:40 pm (16 minutes ago). Anyone else see this? If I was to guess where it was, it would have been over or past the San Diego area of Southern California.

    • Stewart says:

      At 9:40 PM 18 July 2010 Ramona, California (In the Mountains near San Diego) My wife and I were on our way home from an evening with friends when we both saw a bright fire ball cross the sky in front of our car. It was very bright and I could see pieces flaming off of it and then flame out. Lasted about 3 to 4 seconds and was out of sight. This fireball was moving slower then a meteor. I did call the Sheriffs office to report it and they said no one else had called it in. It was quite amazing. I have seen a lot of meteors, but this is the first fireball. From our perspective it was moving from the west to the east. It went directly in front of us.

  7. gabe goldman says:

    This morning, July 19, at 6:15 AM I was traveling north in Simi Valley, CA and saw bright fireball traveling from east to west. It was visible for 4-5 seconds, many times the brightness of Jupiter and 4 times its size. Anyone else see this?

    • Mike says:

      I saw the same fireball this morning, July 19th at about 6:15 am. I was traveling northbound on the 15 freeway around Temecula. Like you said, it lasted for about 4-5 seconds and then dissappeared. It was traveling East to West. I am glad you saw it because nobody believed me. Everyone made me feel like I was seeing things. What was it? A meteor, comet, asteriod, star?

  8. shari duvall says:

    I saw the fireball (July 19, 2010 – 6:15am) while driving on freeway in Sacramento/Roseville area.
    Shari

  9. Dennis says:

    I found this website that show recent fireball sightings. July 2010. http://www.amsmeteors.org/fireball/fireball_log2010.htm

  10. Dennis says:

    Second time is to strange, but I saw a fireball at 8:49 pm tonight. About 2-3 seconds in duration in the southern sky. About 30 degrees above horizon moving straight downward. Blue/green in color with a small trail. Did anyone else see this?

  11. Dennis says:

    Well the third time is a charm. Very interesting to say the least. Saw another fireball traveling in the same direction as the previous two. Aproximately the same location above horizon. This one occured while driving home from dinner about 8:56 pm PDT. Lasted 4 seconds, was not a bright as the other two I reported. Certainly was a fireball with green/blueish color. Didn’t notice a tail and burned out after about 4 seconds. I was driving southbound on Jefferson Street in LaQuinta, California. Wife also witnessed this. From my position in the driver seat of our car, it was in the right front windshield about 3/4 the way up on the windshield moving quickly in the same direction but towards the southwest.

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