Lunar Eclipse on Sunday

[update: changed the time of mid-eclipse to 2:47 UT from 2:48 UT. thanks to Joe Stieber for catching the error. the one minute difference doesn’t change the rest of the article.]

Sunday evening will see the last of the recent tetrad of lunar eclipses for observers in the Americas. The eclipse will occur in the morning for observers in Europe, Africa, and western Asia. This eclipse has been hyped a bit more than usual due to the Moon being a ‘Super Moon’. What that means is the Moon is at the close part of its orbit to Earth and appears a little bit larger than usual. Regardless, all total lunar eclipses are worth seeing and this one will be very nice for western US observers as it will be located low on the horizons making for some nice views. Occurring during the early evening also means we don’t have to be up at weird hours of the night to see this one. This is especially convenient for showing the kids.

The Moon will enter the penumbra of Earth’s shadow at 00:12 UT though most observers will have a difficult time noticing any darkening of the Moon until around ~00:40 UT (8:40 pm EDT, 7:40 pm CDT). At that time the Moon will be below the horizon for Tucson and most observers in the Mountain and Pacific time zones.  The Moon enters the umbra of Earth’s shadow and really starts to get dark at 1:07 UT (9:07 pm EDT, 8:07 pm MDT, 7:07 pm MDT). At Tucson the Moon rises at 1:09 UT (6:09 pm PDT) only 1 minute after the start of the partial eclipse and 7 minutes before sunset. As the Moon gets higher and the sky gets darker it will become easier to see even as Earth’s shadow takes a bigger and bigger bit out of it.

The total phase of the eclipse begins at 2:11 UT (10:11 pm EDT, 9:11 pm CDT, 8:11 pm MDT, 7:11 pm PDT). The middle of the eclipse and the time when the Moon should appear darkest occurs at 2:47 UT (10:47 pm EDT, 9:47 pm CDT, 8:47 pm MDT, 7:47 pm PDT. Totality ends at 3:23 UT (11:23 pm EDT, 10:23 pm CDT, 9:23 pm MDT, 8:23 pm PDT) and the whole show should be over (meaning no obvious darkening of the Moon visible by ~5:20 UT.

Here in Tucson, the Moon will appear to rise at due east and will be observable in the southeastern sky for the entire eclipse.

2015_lunar_eclipse

View of the eastern horizon at the time of mid-eclipse for Tucson, Arizona. Chart created with Stellarium.

If you have a pair of binoculars or are taking images of the eclipse, note that two other relatively bright solar system objects are near the Moon. The planet Uranus is located ~15° to the due east or lower left of the Moon. At that time Uranus will be magnitude 5.7 (barely visible to naked eye observers from dark sites) and located 19.98 AU from the Sun and 19.02 AU from Earth (that’s 1.86 million miles from the Sun and 1.77 million miles from Earth). The Moon will be 0.0024 AU from the Earth (222,000 miles from the center of the Earth) or ~7900 times closer than Uranus. To the southeast of the Moon and about 11° away is the brightest asteroid, (4) Vesta. It will be 2.42 AU (225 million miles) from the Sun and 1.43 AU (133 million miles) from Earth or ~600 times further away than the Moon. Vesta will be a little fainter than Uranus at magnitude 6.2. Use the star chart below to find Uranus and Vesta.

2015_lunar_eclipse_vesta_uranus

Location of Uranus and asteroid Vesta relative to the eclipse Moon on Sunday evening Sep. 27. Chart created with Stellarium.

The next lunar eclipse will be on 2016 March 23 but will be a rather poor penumbral eclipse (meaning the darkest part of the shadow doesn’t cross the Moon). The next series of total lunar eclipses occur on 2018 January 31, 2018 July 27, and 2019 January 19. The first and third of this triad are visible in the US. Go to the NASA Lunar Eclipse page for more detail on these and other lunar eclipse.

In The Sky This Month – June 2011

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of June 2011.

June 2011 Highlights
* Saturn is easy to spot in the evening
* Jupiter is a sight to see just before dawn
* Comet Garradd begins a many month stretch brighter than mag 10

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Moon – The table below lists important lunar dates for the month, including the phases of the Moon and nights of lunar-planetary and lunar-stellar conjunctions.

Jun 1 - New Moon and Partial Solar Eclipse for high latitudes
Jun 5 - Moon 9° from bright star Pollux
Jun 6 - Moon 5° from Beehive Cluster
Jun 7 - Moon 5° from bright star Regulus
Jun 9 - First Quarter
Jun 10 - Moon 8° from Saturn
Jun 11 - Moon 3° from bright star Spica
Jun 14 - Moon 4° from bright star Antares
Jun 15 - Full Moon and Total Eclipse of the Moon (Africa, Asia, Australia)
Jun 23 - Last Quarter Moon
Jun 26 - Moon 5° from Jupiter
Jun 28 - Moon 2° from Mars and Pleiades
Jun 29 - Moon 7° from Aldebaran

Evening Planets

Mercury – Mercury starts the month very low in the ENE dawn sky but is quickly lost over the next few days. It doesn’t take long to reappear and by the last week of June it can be seen low in the WNW 45 minutes or so after sunset. During the last few nights of the month, Mercury makes a nice trio with the bright stars of Gemini, Castor and Pollux. All three can be seen in a 11° long straight line on June 30.

Saturn – Saturn is now well past opposition at magnitude +0.8. It starts the night near its highest point on the meridian to the south. The planet is observable for the rest of the evening.  Saturn is a slow moving planet and takes 29 years to circle the Sun as well as 29 years to do one circuit around the ecliptic constellations. As has been the case all year long, Saturn is still located in Virgo about 13-14° from 1st magnitude Spica. The planet is making a nice “double star”  with 3rd magnitude Gamma Virginis. The two are within 0.25° of each other on June 9.

Jun 10 - Saturn and Moon 8° apart

Morning Planets

Jupiter –  Jupiter rises 2 to 3 hours before sunrise and is well up in  the eastern sky as dawn begins. Shining at magnitude -2.2 the King of the Planets will be the brightest ‘star’ in the sky over the next few months.

Jun 26 - Moon 5° from Jupiter

Mars –  Located 16° to the lower left of Jupiter at the start of the month, the gap increases all month long. Mars is a fast moving planet meaning it does a good job of keeping up with the Sun and as a result will only slowly rise higher in the sky from month to month. Though a relatively faint magnitude +1.4 (for a planet), it will get much brighter as it moves towards opposition in March 2012.

Jun 28 - Moon 2° from Mars

Venus – Venus will be a very difficult sight low in the ENE during dawn. Towards the end of the year, it will be a much easier sight as an evening object.

Meteors

Meteor activity is still near a seasonal minimum in June. The year is usually split in 2 with January through June having low rates with few major showers while July through December 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 mornings, 10-12 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

None 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 2011 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month…

Binocular Comets (V = 6.0 – 8.0)

None this month…

Small Telescope Comets (V = 8.0 – 10.0)

C/2009 P1 (Garradd)

Last month I mentioned how there always seems to be a bright Comet McNaught or Comet Garradd in the sky. Well last month’s Comet McNaught (C/2011 C1) has now faded below 10th magnitude but it has been replaced by a Comet Garradd (C/2009 P1). First seen way back on August 13, 2009 by Gordon Garradd, this is yet another discovery by the Siding Spring Survey, a NASA-funded survey observing from Australia. At the time of discovery it was located at a distance 8.7 AU from the Sun, nearly the distance of Saturn. Perihelion will occur 2 days before Christmas 2011 at 1.55 AU from the Sun. Though the comet does get very close to the Sun, it is an intrinsically bright comet and may be a borderline naked eye object for observers at very dark sites (6th magnitude).

The comet starts the month at a distance of 3.04 AU from the Sun and 2.96 AU from Earth. At mid-month it is 2.91 AU from the Sun and 2.58 AU from Earth and by month’s end it will be 2.76 and 2.19 AU from the Sun and Earth, respectively.  Visual observers are placing the comet at magnitude 10.0 to 10.5 at the end of May. It should brighten to magnitude 9.0 to 9.5 by the end of the month as it slowly moves north near the Pisces/Aquarius border.

Asteroids

Binocular and Small Telescope Asteroids (V < 8.0)

(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 this summer when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012 though images showing more details than those from HST may be released this month.

Images and models of the shape of asteroid (4) Vesta. In the upper left is a real HST image, to the upper right is a model of Vesta’s shape, and on the bottom is an elevation map . Credit: NASA/STScI.

Vesta spends the month around magnitude 6.9 to 6.3 as it begins its retrograde loop in western Capricornus. Opposition is on August 4 at magnitude 5.6.

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.

In The Sky This Month – May 2011

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of May 2011.

May 2011 Highlights
* Venus, Jupiter, Mercury and Mars gather low in the dawn sky
* Saturn is easy to spot in the evening
* Eta Aquariids put on a night display for southern observers

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Moon – The table below lists important lunar dates for the month, including the phases of the Moon and nights of lunar-planetary and lunar-stellar conjunctions.

May 1 - Moon 7° from Mercury, 6° from Jupiter and 5° from Mars
May 3 - New Moon
May 5 - Moon 7° from bright star Aldebaran
May 8 - Moon 9° from bright star Pollux
May 9 - Moon 5° from Beehive Cluster
May 10 - First Quarter Moon
May 11 - Moon 5° from bright star Regulus
May 14 - Moon 8° from Saturn
May 15 - Moon 3° from bright star Spica
May 17 - Full Moon
May 18 - Moon 3° from bright star Antares
May 24 - Third Quarter Moon
May 29 - Moon 5° from Jupiter
May 30 - Moon 4° from Mars
May 31 - Moon 4° from Venus

Saturn – Saturn is now a month past opposition. As a result, the ringed planet is still near its brightest for the year (currently magnitude +0.5 to +0.7) and is also visible throughout the evening and most of the morning hours. Saturn is a slow moving planet and takes 29 years to circle the Sun as well as 29 years to do one circuit around the ecliptic constellations. As has been the case all year long, Saturn is still located in Virgo about 13-14° from 1st magnitude Spica.

May 14 - Saturn and Moon 8° apart

Venus, Mercury, Mars and Jupiter –  The planetary show of the year is a series of compact groupings involving Venus, Mercury, Mars and Jupiter. Unfortunately, all the action will take place very close to the eastern horizon in a bright dawn sky for northern observers. South of the equator the view will be much easier to see.

From May 7 to 15, Venus, Mercury and Jupiter will be within 5° of each other. On May 11, the trio will be within ~2° of each other. A similar trio of Venus, Mercury and Mars will be within 5° of each other from May 15-25 with their tightest grouping of ~2° on May 21.

May 1 - Moon 7° from Mercury, 6° from Jupiter and 5° from Mars
May 1 - Jupiter and Mars within 0.4° of each other
May 6 - Mercury at greatest elongation west
May 7 - Mercury and Venus within 1.4° of each other
May 11 - Venus, Mercury and Jupiter within 2.1° of each other
May 18 - Mercury and Venus, again, within 1.4° of each other
May 21 - Venus, Mars and Mercury within 2.1° of each other
May 23 - Venus and Mars within 1° of each other
May 29 - Moon 5° from Jupiter
May 30 - Moon 4° from Mars
May 31 - Moon 4° from Venus

Meteors

Meteor activity is near a seasonal minimum in May. The year is usually split in 2 with January through June having low rates with few major showers while July through December 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 May mornings, 10-12 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

Eta Aquariids (ETA)

The Eta Aquariids are a major shower, especially for southern hemisphere observers, when they peak on May 6. For northern observers, the shower will only be observable for an hour or two before dawn. Since the radiant doesn’t get very high for NH observers, rates can be low. The radiant is located near the “jar” of Aquarius.

The ETA were produced by Comet Halley which also gives us the Orionids in October. Models suggest that the ETA were released by Comet Halley no later than 837 AD. The Orionids are easy to see because the particles are hitting the Earth from the anti-solar direction. This means the meteor shower can be seen in the middle of the night. The ETA are produced by meteoroids moving outbound from the Sun, as a result the radiant is located relatively close to the Sun. As a result the ETA radiant is only visible for an hour or so before twilight. This year the Moon is near New so the sky will be dark.

The shower spans from April 19 to May 28 with a peak around May 5 with a maximum ZHR of ~60. The poor placement of the radiant for northern observers will greatly limit the number of observed meteors.

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 2011 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month…

Binocular Comets (V = 6.0 – 8.0)

None this month…

Small Telescope Comets (V = 8.0 – 10.0)

C/2011 C1 (McNaught)

It seems like every year sees a bright Comet McNaught and this year is no different. The 58th comet discovery by Rob McNaught and 74th from Siding Spring Observatory, C/2011 C1 was first seen on February 10th of this year. Though intrinsically faint, the comet is currently being reported as bright as magnitude 9.0. CCD images taken by the author on Apr 1 UT confirm that the comet was between magnitude 9.0 and 9.5 at that time (see image below). Unfortunately the comet should fade this month as it passed perihelion on April 17 at a distance of 0.88 AU from the Sun. The comet starts May 0.92 AU from the Sun and 1.23 AU from Earth. These distances will have increased to 1.02 AU from the Sun and 1.39 AU from Earth by mid-month and 1.17 AU from the Sun and 1.52 AU from Earth at the end of the May.  Comet C/2011 C1 is a morning object low in the east and travels from Pegasus to Pisces this month.

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Asteroids

Binocular and Small Telescope Asteroids (V < 8.0)

(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 this summer when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012.

Images and models of the shape of asteroid (4) Vesta. In the upper left is a real HST image, to the upper right is a model of Vesta’s shape, and on the bottom is an elevation map . Credit: NASA/STScI.

Vesta spends the month around magnitude 7.3 to 6.9 as it moves eastwards through western Capricornus. Opposition is on August 4 at magnitude 5.6.

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.

In The Sky This Month – April 2011

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of April 2011.

April 2011 Highlights
* Saturn is the only easily visible planet
* The rest of the naked eye planets congregate in the morning sky at the end of the mont

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Moon – The table below lists important lunar dates for the month, including the phases of the Moon and nights of lunar-planetary and lunar-stellar conjunctions.

Apr 3 - New Moon
Apr 7 - Moon 2° from Pleiades
Apr 8 - Moon 7° from bright star Aldebaran
Apr 11 - First Quarter Moon 9° from bright star Pollux
Apr 12 - Moon 5° from Beehive Cluster
Apr 14 - Moon 5° from bright star Regulus
Apr 17 - Moon 8° from Saturn and 2.5° from bright star Spica
Apr 18 - Full Moon
Apr 20 - Moon 3° from bright star Antares
Apr 25 - Third Quarter Moon
Apr 30 - Moon 6.6° from Venus

Saturn – This month Saturn is at opposition. As a result, the ringed planet is at its brightest for the year (magnitude +0.4) and is also visible all night long though it is best around midnight. At the start of the month Saturn may be too low in the SE at dusk to be easily seen but by month’s end it is far enough off the horizon at dusk to be easily seen. Saturn is a slow moving planet and takes 29 years to circle the Sun as well as 29 years to do one circuit around the ecliptic constellations. As has been the case all year long, Saturn is still located in Virgo about 11-13° from 1st magnitude Spica.

Apr 3 - Saturn at Opposition
Apr 17 - Saturn and Moon 8° apart

Venus, Mercury, Mars and Jupiter –  The long slow grind towards superior conjunction continues. This month Venus rises only an hour or so before the Sun and never gets very high in the ESE to E sky. Though Venus is a difficult sight for northern observers it is worth searching out at the end of April. During the last week of the month (and into May) Venus will be visited by 3 planets in the best planetary alignment of the year. Starting around the 25th, Mercury peaks above the eastern horizon 40 minutes before sunrise. Over the next few nights, Mars and Jupiter join the show. Use the crescent Moon on the 29th and 30th to point the way.

Apr 30 - Moon 6.6° from Venus

Meteors

Meteor activity is near a seasonal minimum in April. The year is usually split in 2 with January through June having low rates with few major showers while July through December 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 April mornings, 10-12 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

Lyrids (LYR)

The Lyrids are usually good for 10-20 meteors per hour under a dark sky. This month the just past Full Moon will make the shower difficult to observe. So these remnants of Comet Thatcher will probably go unobserved except by automated video systems and only the most dedicated of visual observers.

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 2011 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month…

Binocular Comets (V = 6.0 – 8.0)

None this month…

Small Telescope Comets (V = 8.0 – 10.0)

C/2011 C1 (McNaught)

It seems the past couple of years have seen a bright Comet McNaught and this year is no different. The 58th comet discovery by Rob McNaught and 74th from Siding Spring Observatory, C/2011 C1 was first seen on February 10th of this year. Though intrinsically faint, the comet is currently being reported as bright as magnitude 9.0. CCD images taken by the author on Apr 1 UT confirm that the comet is between magnitude 9.0 and 9.5 at this time (see image below). Unfortunately this will probably be as bright as the comet gets as it passes perihelion on April 17 at a distance of 0.88 AU from the Sun. It is also slowly moving away from Earth with a geocentric distance of 0.95, 1.06 and 1.22 AU from Earth at the star, middle and end of the month. Comet C/2011 C1 travels the length of Aquarius before ending the month near the Pisces/Pegasus border.

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Asteroids

Binocular and Small Telescope Asteroids (V < 8.0)

(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 this summer when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012.

Images and models of the shape of asteroid (4) Vesta. In the upper left is a real HST image, to the upper right is a model of Vesta’s shape, and on the bottom is an elevation map . Credit: NASA/STScI.

Vesta spends the month around magnitude 7.6 to 7.3 as it moves eastwards through western Capricornus.

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.

In The Sky This Month – March 2011

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of March 2011.

March 2011 Highlights
* Mercury and Jupiter dazzle after evening twilight
* Saturn is up all night
* Venus slowly loses altitude before dawn

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Moon – The table below lists important lunar dates for the month, including the phases of the Moon and nights of lunar-planetary and lunar-stellar conjunctions.

Mar 1 - Moon 1.6° from Venus
Mar 4 - New Moon
Mar 6 - Moon 6° from Jupiter
Mar 11 - Moon 2° from Pleiades
Mar 12 - First Quarter Moon
Mar 12 - Moon 7° from bright star Aldebaran
Mar 15 - Moon 9° from bright star Pollux
Mar 16 - Moon 5° from Beehive Cluster
Mar 17 - Moon 5° from bright star Regulus
Mar 19 - Full Moon
Mar 20 - Moon 7.5° from Saturn
Mar 21 - Moon 2.5° from bright star Spica
Mar 24 - Moon 3° from bright star Antares
Mar 26 - Third Quarter Moon
Mar 28 - Moon 1.5° from asteroid Vesta
Mar 31 - Moon 5.5° from Venus

Mercury and Jupiter – The innermost planet has its best evening apparition of the year this month (for observers in the northern hemisphere). From mid-month till the end of the month, Mercury will be observable low in the western sky a half-hour or so after sunset. As an added bonus, Jupiter will be located nearby. The two will be closest on Mar 15 when they will only be 2° from each other. By the end of the month both planets will be located too close to the Sun to be easily seen.

Mar 6 - Moon 6° from Jupiter
Mar 15 - Mercury and Jupiter within 2° of each other
Mar 23 - Mercury at Greatest Elongation East

Saturn – Saturn starts the month rising a few hours after sunset. By the end of the month it is only a few days from opposition (on April 3) and rises just moments after sunset. Located in Virgo, the ringed planet is a close match in brightness (mag +0.4) to Spica, the brightest star in Virgo (mag +1.0). Saturn spends the entire month within 10° of Spica.

Mar 20 - Moon 7.5° from Saturn

Venus –  On Mar 1, Venus rises almost 2 hours before the Sun in the eastern sky though this drops to just a little over an hour by the end of the month.

Mar 1 - Moon 1.6° from Venus
Mar 31 - Moon 5.5° from Venus

Mars – Too close to the Sun for observation.

Meteors

Meteor activity is near a seasonal minimum in March. The year is usually split in 2 with January through June having low rates with few major showers while July through December 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 March mornings, 10-12 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

None 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 2011 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month…

Binocular Comets (V = 6.0 – 8.0)

None this month…

Small Telescope Comets (V = 8.0 – 10.0)

None this month…

Asteroids

Binocular and Small Telescope Asteroids (V < 8.0)

(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 this summer when NASA’s Dawn spacecraft enters orbit around Vesta for a full year. Currently the encounter is scheduled for July 2011 to July 2012.

Images and models of the shape of asteroid (4) Vesta. In the upper left is a real HST image, to the upper right is a model of Vesta’s shape, and on the bottom is an elevation map . Credit: NASA/STScI.

Vesta spends the month around magnitude 7.7 as it moves eastwards through eastern Sagittarius.

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.

Evening planets – August 8

Watch the western sky right after it gets to dark to watch the heavens in motion. For the entire month, the planets of Venus, Mars, Saturn (and if you can see close enough to the horizon, Mercury) will slowly move among the background stars of Leo and Virgo.

The northern hemisphere view for tonight is shown below. In addition to the 4 bright planets, binocular and telescope observers can hunt for the 8th magnitude asteroid Vesta.

Northern hemisphere view of the evening conjunction for the night of August 8. Created with Stellarium.

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Astrophotographers such as Fred Quintao of Belo Horizonte, Brazil have been following the action nightly. The photo below shows all 4 planets just above the brilliant skyline of Belo Horizonte on the evening of August 6. If you’d like to share your photos with the readers of the Transient Sky, send them to our new email address (transientsky1@yahoo.com).

Venus, Mars, Saturn and Mercury setting over the skyline of Belo Horizonte, Brazil on August 6. Images credit: Fred Quintao.

Celestial Triangle (+ Mercury and Vesta) – August 6

The early evening planetary show continues tonight. The celestial triangle of Venus, Mars and Saturn should be easy to spot with a good view of the western horizon. Mercury is also visible much closer to the horizon.

Fred Quintao of Brazil pointed out that the large asteroid Vesta is also visible nearby. His image from August 2 shows Vesta to the north of the Venus-Mars-Saturn triangle.

Image of the Vesta near the Venus-Mars-Saturn triangle. Image taken by Fred Quintao from Brazil on August 2, 2010. Credit: Fred Quintao.

Image of the Vesta near the Venus-Mars-Saturn triangle. Image taken by Fred Quintao from Brazil on August 2, 2010. Credit: Fred Quintao.

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For a view of tonight’s alignment see the chart below.

View of the western horizon after darkness falls on the evening of August 6, 2010. Created with Stellarium.

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For those wanting to find Vesta, the following chart is better. Vesta is too faint at magnitude +8.0 to be seen without the help of binoculars or a small telescope. Though not the biggest asteroid, Vesta is intrinsically the brightest due to a very high albedo (meaning it reflects a large fraction [42%] of the light that encounters it).

Fainter chart showing the position of asteroid (4) Vesta on the evening of August 6. Created with Stellarium.

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