In The Sky This Month – June 2010

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

June 2010 Highlights

* Venus, Mars and Saturn close in on each other in the evening sky
* Comet 2009 R1 (McNaught) reaches naked eye brightness in the morning sky
* Jupiter passes close to Uranus
* Asteroid (1) Ceres at opposition on the 19th and is an easy binocular object
* Partial Lunar Eclipse for the Far East and most of North/South America on the 26th
* Japanese Hayabusa spacecraft to return samples from asteroid Itokawa on the 13th
* EPOXI (spacecraft formally known as Deep Impact) flys past Earth on the 27th

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.

Planetary Spacecraft

Hayabusa – On the June 13th, the Japanese Hayabusa spacecraft is scheduled to return to Earth. Tucked away in its sample return capsule may be a few grams of regolith (asteroid soil) from the small Near-Earth asteroid (25143) Itokawa). Launched in 2003, Hayabusa spent a few months in late 2005 studying Itokawa. Though the plan was to retrieve samples of the asteroid for return to Earth, the mission was plagued with many difficulties. As a result, mission operators are unsure if any samples were picked up. Even whether or not the spacecraft can successful hit it target and land in Australia is in doubt. Regardless, the spacecraft and its sample return capsule will be coming back to Earth on the 13th.

NASA will be watching the re-entry of Hayabusa and studying the resulting fireball. Hopefully we will get some great video shortly afterwards. Check out the Hayabusa Re-Entry airborne observing campaign at the SETI Institute and the press releases from the Japanese Aerospace Exploration Agency for the latest.

EPOXI (ex-Deep Impact) –

The main comet event of 2010 will be periodic comet 103P/Hartley 2. Not only will the comet become a nice naked eye object this fall, but a re-used NASA spacecraft will encounter the comet. EPOXI has gone through quite a few name changes in its time. Originally Deep Impact it was launched in January 2005. In July 2005, it released a small package which impacted the surface of periodic comet 9P/Tempel 1. The impact allowed scientists an opportunity to study the interior of a comet. After the conclusion of its primary mission, NASA agreed to fund 2 experiments that utilized the spacecraft. One of its cameras was used to study planets studying other stars (an experiment called EPOCh, for Extrsolar Planet Observation and Charaterization). Also it will fly-by the aforementioned comet Hartley 2 (an experiment called DIXI for Deep Impact eXtended Investigation). Eventually the names were merged into EPOXI but really we are just talking about the old Deep Impact spacecraft.

On the 27th, EPOXI will fly-by the Earth setting up an encounter of Hartley 2 on November 4th.

Planets (and Moon)

Moon – The Moon will experience a Partial Lunar Eclipse on the night of June 25/26. At its best, a little over 53% of the Moon will be in umbral (darkest) eclipse. For the best info on this eclipse go to NASA’s Eclipse Website.

Venus – Venus is the brightest “star” visible in the early evening. Low in the west it sets about 2.5 hours after the Sun. From now till July/August it will ride as high as it’ll get for northern observers. In fact, this is not a great evening apparition for Venus. On the other hand, it is a great apparition for observers south of the Equator. For them, 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.

June 11 - Venus in line with bright stars Castor and Pollux
June 15 - Moon passes within 4° of Venus
June 20 - Venus passes the center of the Beehive star cluster

Mars – Mars moves rapidly through the constellation of Leo this month. Though fading from magnitude +1.1 to +1.3 it is still an obvious red beacon to the southwest of overhead right after sundown. It’s brightness is comparable to that of the other bright stars. Watch Mars pass within 0.8° of the bright star Regulus on the 7th. Mars will be magnitude +1.2 on that date and just slightly brighter than Regulus at magnitude +1.4. By the end of the month, Mars is located within 16° of Saturn. The two will be closest at the end of July, and will be joined by Venus in early August.

June 7 - Mars passes 0.8° from the 1st mag star Regulus
June 17 - Moon passes within 6° of Mars

Saturn – This month Saturn is visible in the south during the early evening hours. It will slowly fade from magnitude +1.0 to +1.1 making it slightly brighter than Mars. Telescope users should note that Saturn’s rings are still within a few degrees of edge-on.

June 19 - Moon passes within 8° of Saturn

Jupiter and Uranus – Jupiter once again returns to sight as a brilliant star low in the east-southeast before dawn. The magnitude -2.4 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. On June 6th, Jupiter will make it’s first closes approach to Uranus at a small distance of 0.44°.

June 6 - Moon passes within 7° of Jupiter
June 8 - Jupiter passes within 0.5° of Uranus

Mercury -Mercury is in the middle of a morning apparition at the start of the month. This morning apparition will not be good for northern observers though it is excellent for southern observers. By mid-month, Mercury will have fallen back into the glare of the Sun.

June 11 - Moon passes within 9° of Mercury

Meteors

June starts to see an increase in meteor activity after a few months of low activity. 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 June, 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)

Comet C/2009 R1 (McNaught)

Comet C/2009 R1 (McNaught) will be a bright binocular comet and probably even a faint naked eye comet for observers under dark skies. Observations made over the past few weeks shows this comet to be rapidly brightening. By the start of June, the comet should be around magnitude 6.5 to 7.0. By mid-month, it will have brightened to magnitude 5.0 and maybe even 4.0. By the end of the month, it will be a bright magnitude 4.0 and perhaps brighter. The lightcurve below shows 3 possible brightness trends that the comet could follow. Though the red curve which shows a peak brightness of magnitude 2 would be nice it is most likely the comet will follow one of the fainter curves and peak at magnitude ~4.

The comet is a morning object and is only visible for an hour or so before the start of dawn. By the end of the month the comet can also be glimpsed in the evening. As the month progresses the comet will become harder to see as it moves closer to the Sun. Observers will need a clear NE (or NW in the evening later in the month) horizon to see the comet. Fourth magnitude is bright enough to be seen with the naked eye under dark conditions. Unfortunately the majority of  us live under bright, murky skies so binoculars will be required to see the comet for most people. The fact that the comet will set will twilight is still bright surely doesn’t help either. Currently the comet is located in Andromeda but it will quickly move through that constellation as well as Perseus and Auriga.

Still inbound, perihelion will occur on July 2nd of this year at a relatively small distance of 0.41 AU from the Sun. This month it will be 0.88 AU from the Sun and 1.26 AU from Earth on June 1st, 0.61 AU from the Sun and 1.14 AU from Earth on the 15th, and 0.41 AU from the Sun and 1.26 AU from Earth on the 30th.

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.

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

Comet C/2009 K5 (McNaught)

The 2nd ‘Comet McNaught’  is Comet C/2009 K5 (McNaught). It was discovered on May 27, 2009 deep in the southern sky. Similar to C/2009 R1, this comet was also found with the Uppsala schmidt at around magnitude 17.

With perihelion on April 30 of this year at a distance of 1.42 AU from the Sun, C/2009 K5 is still bright enough to be seen in small backyard telescopes from dark sites.   At mid-month it will be located 1.57 AU from the Sun and 2.05 AU from Earth.

Observations over the past 2 months show the comet to be around magnitude 8.0 to 8.5. With the comet in full retreat from the Sun and Earth, it should fade from here on out. The comet will start the month between 8.0 and 8.5 but should fade to around 9.0 by the end of the month. Due to its located in the far northern constellation of Camelopardalis, the comet can be seen at all hours of the night from 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)

(4) Vesta

Vesta is the brightest asteroid in the Main Belt. This is due to its high albedo (or reflectivity) which causes it to reflect ~42% of the light that strikes it. Vesta is also peculiar in that it appears to have evidence of volcanism on its surface. Similar to the Moon, Vesta may be covered with large expanses of frozen lava flows. It is classified as a V-type asteroid and is the only large asteroid with this classification. Many of the smaller V-type asteroids are chips of Vesta blasted off it by past asteroid and comet impacts. Vesta has dimensions of 347x336x275 miles or 578×560×458 km.

The maps below were created from images taken with the Hubble Space Telescope. The geography is dominated by a large impact crater located near the south pole (the blue ‘donut’ in the elevation map). Perhaps this crater is the result of the impact that blasted off the smaller V-type asteroids. We’ll know more next year when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012.

Vesta starts the month at magnitude 7.7 and steadily fades to mag 7.9. A pair of binoculars will allow you to see Vesta among the stars of Leo.

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 Vesta from Heavens Above.

(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 7.5, brighten to magnitude 7.1 at opposition of June 19, and then fade to magnitude 7.4 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.