Oct 1 – 9 Meteors

During the night of October 8 UT the Draconids produced an outburst of activity for observers on the eastern side of the Atlantic. Based on visual reports, the IMO’s live ZHR chart showed a peak ZHR of between 300 and 400 meteor per hour. The bright Moon and preponderance of faint Draconids meant the actual observed rates were much lower.

Here in AZ the show was over by the time night fell. In fact, not a single Draconid was seen by my camera system only hours after the outburst. Except for a single meteor observed the night before the outburst, this year’s Draconids were their usual meager self for me.

With the Draconids past us, we are now looking forward to the Orionids which should peak on the 21st. Already a few Orionids have been seen each night since the 4th.

Bright (-3mag) SPO on 2011 Oct 6 @ 06:17 UT.

NTA meteor on 2011 Oct 6 @ 10:56 UT.

Obs  Date(UT)      Time    TOT SPO NTA STA ORI DAU OCA GIA EPC
TUS  2011-10-09   10h 46m   38  27  0   4   4   3   0   0   0
TUS  2011-10-08   09h 03m   28  18  3   5   1   0   0   1   0
TUS  2011-10-07   03h 01m   18  14  1   1   2   0   0   0   -
TUS  2011-10-06   06h 48m   20  14  2   0   2   1   1   -   -
TUS  2011-10-05   07h 10m   26  15  1   6   3   1   -   -   -
TUS  2011-10-04   02h 34m   8   7   0   0   1   0   -   -   -
TUS  2011-10-03   08h 18m   22  17  1   2   0   2   -   -   -

SAL3 - SALSA3 camera in Tucson (Carl Hergenrother)
ALLS - Near all-sky camera in Tucson (Carl Hergenrother)
VIST - Visual observations from Tucson (Carl Hergenrother)
VISH - Visual observations from Hermosillo (Salvador Aguirre)
HERM - PARENI camera in Hermosillo (Salvador Aguirre)
SDG - Camera in San Diego operated by Bob Lunsford
Time - Total amount of time each camera looked for meteors
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelions
NTA - Northern Taurids 
STA - Southern Taurids 
ORI - Orionids
DAU - Delta Aurigids 
OCA - October Camelopardalids 
GIA - Draconids 
EPC - October Eta Piscids

Meteor Activity Outlook for October 8-14, 2011

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning October 8/9. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.

Meteor activity in general increases in October when compared to September. A major shower (the Orionids) is active most of the month along with many minor showers. Both branches of the Taurids become more active as the month progresses, providing slow, graceful meteors to the nighttime scene. The Orionids are the big story of the month reaching maximum activity on the 22nd. This display can be seen equally well from both hemispheres which definitely helps out observers located in the sporadic-poor southern hemisphere this time of year.

During this period the moon reaches its full phase on Wednesday October 12th. At this time the moon will lie opposite of the sun and will be in the sky all night long. This weekend the waxing gibbous moon will set during the early morning hours and will allow a couple of hours of meteor observing in dark skies before morning twilight. The estimated total hourly rates for evening observers this week is near two as seen from the northern hemisphere and one as seen from the southern hemisphere. For morning observers the estimated total hourly rates should be near six as seen from mid-northern latitudes and four from mid-southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Rates are reduced during this period due to the intense moonlight.

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning October 8/9. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

Detailed descriptions of each shower will continue when the moonlight situation improves.The following showers are expected to be active this week. Rates and positions are exact for Saturday night/Sunday morning.

The list below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
GIA Draconids             17h 28m  +54    20    <1    <1
STA Southern Taurids      02h 04m  +09    27     1     1
ORI Orionids              05h 44m  +16    67     1     1
OCT Oct. Camelopardalids  10h 48m  +79    45    <1    <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

Meteor Activity Outlook for October 1-7, 2011

The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.

Meteor activity in general increases in October when compared to September. A major shower (the Orionids) is active most of the month along with many minor showers. Both branches of the Taurids become more active as the month progresses, providing slow, graceful meteors to the nighttime scene. The Orionids are the big story of the month reaching maximum activity on the 22nd. This display can be seen equally well from both hemispheres which definitely helps out observers located in the sporadic-poor southern hemisphere this time of year.

During this period the moon reaches its first quarter phase on Tuesday October 4th. At this time the half illuminated moon will lie ninety degrees east of  the sun and will set near midnight local daylight time (LDT). This weekend the waxing crescent moon will set during the early evening hours and will not interfere with meteor observing. The estimated total hourly rates for evening observers this week is near four as seen from the northern hemisphere and three as seen from the southern hemisphere. For morning observers the estimated total hourly rates should be near twelve as seen from mid-northern latitudes and seven from mid-southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity.

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning October 1/2. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week:

The Draconids (GIA) (also known as the Giacobinids) reach maximum activity on October 8. This year a possible outburst is predicted to be visible from Asia, Africa, and Europe. Lesser activity may be seen on the 6th and 7th and the 9th and 10th. The nearly full moon this time of month will severely hamper observations. Detailed articles are available on the websites of the International Meteor Organization (http://www.imo.net/draconids2011) and the American Meteor Society (http://www.amsmeteors.org/2011/09/possible-draconid-outburst-in-2011/). The radiant is located at 17:28 (262) +54, which places it in southern Draco, two degrees northwest of the third magnitude star Rastaban (Beta Draconis). This star is one of the four that form the prominent head of Draco, also known as the “Lozenge”. Due to the extreme northern declination, this shower is only visible from the southern tropics northward. The radiant is best placed just as it becomes dark during the evening hours. At 20km/sec., the average Draconid is extremely slow.

The Southern Taurid (STA) radiant is now centered at 01:40 (025) +07. This area of the sky lies in southeastern Pisces, two degrees southwest of the fourth magnitude star Omicron Piscium. This radiant is best placed near 0200 local daylight time (LDT), when it lies on the meridian and is located highest in the sky. Rates at this time should be near two per hour no matter your location. With an entry velocity of 27 km/sec., the average Southern Taurid meteor would be of medium-slow speed. While looking at this area of the sky, notice how bright the variable star Mira (Omicron Ceti) is these nights. It normally is too dim to be seen with the naked eye but now stands at second magnitude, nearly the brightest star in the constellation of Cetus the whale. It lies approximately ten degrees southeast from the center of the STA radiant or just six degrees southeast of the fourth magnitude star Al Rischa (Alpha Piscium). It is probably near peak magnitude and will soon begin fading.

A new shower of bright meteors radiating from near the Draco/Camelopardalis border was discovered in 2005 and has repeated itself in most years since. The October Camelopardalids (OCT) are active on only two nights but shower members are bright and should be easy to observe. The 2011 display is predicted to occur on October 5th and 6th. The estimated position of the radiant on the 5th is 10:48 (162) +79. The nearest easy star to identify the radiant is 4th magnitude SAO1551. This area of the sky is circumpolar from nearly the entire northern hemisphere. The radiant lies highest above the horizon in a dark sky at both dusk and at dawn. Due to this unusual situation this shower would be totally invisible from the southern hemisphere. With an entry velocity of 45km/sec., most members of the October Camelopardalids would be of medium-swift velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately ten sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near two per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near five per hour as seen from rural observing sites and one per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.

The list below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
GIA Draconids             17h 28m  +54    20    <1    <1
STA Southern Taurids      01h 40m  +07    27     2     2
OCT Oct. Camelopardalids  10h 48m  +79    45    <1    <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

Oct 2/3/4/5 Meteors

Clouds + Full Moon = lots of missed meteors

There’s not much more to say. The consistent cloud cover in conjunction with a very bright Moon really does wreck havoc on the automated meteor detection code we use. Similar to Bob’s experience below, every night produces thousands of false detections. Luckily it is worth scanning through the list of possible meteors for the few real ones. Clouds may continue to be a problem till the end of the week.

From Bob’s notes from 10/3: “A cloudy day gave way to mostly clear skies tonight. There were occasional alto cumulus clouds, which shone brightly in the moonlight, which triggered over a thousand false detections. The full moon was the major reason for the lower counts tonight.”

The past few nights has seen the start of monitoring for 2 annual showers. The October Camelopardalids (OCA) are a short-duration (~3 day) shower that will peak tonight. This shower usually shows little activity though outbursts of higher activity were reported in 1902, 1942, 1976 and 2005. There may be a future outburst in 2018. Due to the nearly Full Moon and lack of a predicted outburst, there may be few OCAs to see though one never knows.

Also starting last night are the Orionids (ORI). This shower is one of the year’s best and though activity is very low now, its peak on Oct 21/22 will be worth watching.

Obs Date (UT)   TotTime  TOT SPO DAU NTA STA ORI OCA
TUS 2009-10-05  02h 31m   6   2   3   0   0   1   0
TUS 2009-10-04  09h 29m   19  13  1   2   1   2
TUS 2009-10-03  00h 00m   Clouds/Rain all night
SDG 2009-10-03  08h 37m   39  36  -   -   3

TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – Total amount of time each camera looked for meteors
TOT – Total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
DAU – Delta Aurigids
NTA – Northern Taurids (includes Antihelions)
STA – Southern Taurids (includes Antihelions)
ORI – Orionids
OCA – October Camelopardalids

Meteor Activity Outlook for October 3-9, 2009

The Meteor Activity Outlook is a weekly summary of expected meteor activity written by Robert Lunsford, Operations Manager of the American Meteor Society and contributor to this blog. New Outlooks are released every Thursday (and if I had hit the “publish” button last week, you would have been reading this post last Thursday :)). The original unedited version of this week’s Meteor Activity Outlook can be found at the American Meteor Society’s site.

Meteor activity in general increases in October when compared to September.
A major shower (the Orionids) is active most of the month along with several
minor showers. Both branches of the Taurids become more active as the month
progresses, providing slow, graceful meteors to the nighttime scene. The
Orionids are the big story of the month reaching maximum activity on the
22nd. This display can be seen equally well from both hemispheres which
definitely helps out observers located in the sporadic-poor southern
hemisphere this time of year.

During this period the moon reaches its full phase on Sunday October 4th. At
this time the moon lies in the sky all night long and severely hampers
meteor observations. A small window of dark skies opens later in the week as
the waning gibbous moon rises later in the evening allowing a couple of
hours of dark sky between the end of evening twilight and moonrise. The
estimated total hourly rates for evening observers this week is near three
as seen from the northern hemisphere and two from the southern hemisphere.
For morning observers the estimated total hourly rates should be near seven
from the northern hemisphere and four as seen from the southern hemisphere.
The actual rates will also depend on factors such as personal light and
motion perception, local weather conditions, alertness and experience in
watching meteor activity. All rates are severely reduced by bright
moonlight.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning October 3/4. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The full descriptions of each active meteor shower will continue next week
when the moon becomes less of a nuisance to observers.

The list below presents a condensed version of the expected activity this
week. Rates and positions are exact for Saturday night/Sunday morning or the
night of maximum activity for showers of short duration.

Shower Name               RA   DEC Vel    Rates
                                   km/s  NH   SH
GIA Draconids           17h28m +56  19   <1   <1
OPC Oct ε-Piscids       00h05m +14  19   <1   <1
STA Southern Taurids    01h46m +08  29    1    1
ORI Orionids            05h28m +16  67   <1   <1
OCT Oct Camelopardalids 11h13m +79  45   <1   <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a
        dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

Oct 6/7/8 Meteors

Catching up on results from the past two nights. There hasn’t been much activity from the October Camelopardalids (OCA) or Giacobinids (GIA) this year. The OCAs were predicted to peak over the Pacific basin on the morning of Oct 5. Most of the western US and Canada were plagued with clouds and there are no reports (that I know of) of activity over Asia, Alaska or Hawaii.

Obs  Date (UT)   TotTime TOT SPO NTA STA DAU ORI OCA GIA
Carl 2008-10-07   9h 26m  21  18  2   0   1   0   0   0
Bob  2008-10-07  10h 28m  72  51  5   9   0   4   1   2
Carl 2008-10-08  10h 45m  22  14  0   2   1   5       0
Bob  2008-10-08  10h 23m  90  61  8   14  2   4       1

TotTime – Total amount of time each camera looked for meteors
TOT – total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA – Northern Taurids
STA – Southern Taurids
DAU – δ-Aurigids (Delta Aurigids)
ORI – Orionids
OCA – October Camelopardalids
GIA – Giacobinids (also known as Draconids)

Bob’s camera caught a nice bright SPO meteor on the morning of Oct 7. The meteor starts just to the lower right (southwest) of the Pleiades.

51 UT.

SPO meteor over Chula Vista on Oct 7 at 09:51 UT.

Oct 5/6 Meteors

The weather has cleared here in the southwest US. Bob’s Chula Vista site was clouded out the previous two nights and my Tucson sight lost a night.

Two additional meteors showers are now active, the October Camelopardalids (OCA) and the Giacobinids/Draconinds (GIA). The OCA were predicted to peak on the morning of the 5th. Unfortunately, both my and Bob’s cameras were clouded out. I have not read of any reports about the peak of this shower.

Obs  Date (UT)   TotTime TOT SPO NTA STA DAU ORI OCA GIA
Carl 2008-10-06   9h 57m  20  12  2   1   0  3   2   0
Bob  2008-10-06  10h 32m  79  61  5   10  0  1   2   0

TotTime – Total amount of time each camera looked for meteors
TOT – total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA – Northern Taurids
STA – Southern Taurids
DAU – δ-Aurigids (Delta Aurigids)
ORI – Orionids
OCA – October Camelopardalids
GIA – Giacobinids (also known as Draconids)

In The Sky This Month – October 2008

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of October 2008.

Planets

Venus is the very bright “star” close to the southwestern horizon for an hour or so after sunset. When it is above the horizon, it is the brightest “star” in the sky.

Jupiter is located in the constellation of Sagittarius. At the beginning of the month, Jupiter starts the night almost due south in the southern part of the sky. As the night progresses, it slowly moves to the west and sets around 11 pm local time. By Halloween, Jupiter starts the night low in the southwestern sky and sets around 9 pm. Jupiter is fainter than Venus but brighter than any star.

Saturn is located low in the east just before sunrise. It is as bright as many of the brightest stars.

Mercury is too close to the Sun at the beginning of the month. By the mid-month, it will become observable as a bright “star” low in the ESE sky just before sunrise. It reaches the best time for observation on Oct 22 when it is furthest from the Sun. It will continue to be observable for the rest of the month as it slowly drops towards the horizon.

Mars is too close to the Sun to be seen.

Meteors

October sees a number of meteor showers including one of the year’s best, the Orionids.

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 October, ten (10) or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

Orionids (ORI)

The Orionids are the best shower during the month of October. When you see an Orionid meteor, you are seeing small pieces of Halley’s Comet which were released thousands of years ago. The Eta Aquarids of May are also from Comet 1P/Halley.

This shower is active from Oct 3 to Nov 11 with a broad peak between Oct 18 and 24. They radiate from northern Orion. During their peak, rates can be as high as 30-100 meteors per hour. Last year rates reached 70 meteors per hour and similar circumstances are predicted for this year with the best time being the morning of Oct 19 (for the US). However, a bright quarter Moon will wash out many of the fainter meteors resulting in smaller rates. Much of this year’s ORI meteors were released by Comet Halley between 1265 BC and 910 BC (for some points of reference, the Trojan War took place around 1200 BC and King David ruled around 1000 BC).

Minor Meteor Showers

Minor showers produce so few meteors that they are barely noticeable above the background of regular meteors.

Northern and Southern Taurids (NTA/STA)

The Taurids never produce more than ~5 meteors per hour. They make up for their low rates by being active for over two months and by producing many bright fireballs. Their fireballs are more apparent to the average observer because, unlike most meteor showers, the Taurids are observable all night long rather than just in the morning. They are active for the entire month of October with activity slowly building as the month progresses. Though named after the constellation of Taurus, the Taurids radiate from the constellation of Aries for most of October.

The Taurids are produced by Comet 2P/Encke. Encke is an enigmatic object with the shortest period for any known comet at 3.3 years. First observed in 1786, it has been observed over ~60 orbits and has been seen every year since 1993.

Delta Aurigids (DAU)

Until a few years ago, the September Perseids and the Delta Aurigids were considered part of the same shower. Analysis of the orbits of their meteors suggested that there are in fact two overlapping showers each originating from a different unknown long-period comet. Like the SPEs, this minor shower usually produces no more than ~3 meteors per hour at its maximum. There is some disagreement as to when this shower is active. Naked eye observations over the past few decades suggest a period of activity from Sept 18 through Oct 10 with a broad peak between Sept 23 and Oct 3. Recent video data finds a later period of activity between Oct 6 and 12 with no obvious peak. The DAUs radiate from the northern part of the constellation of Auriga just to the north of the bright star Capella.

October Camelopardalids (OCT)

This is a new shower first recognized in 2005, though sightings as early as 1902 have been recorded. A few OCAs are observable between Oct 1 and 10. The vast majority of meteors occur during a short  ~2 hour span at the time of peak activity. This year’s peak is predicted to occur within a few hours of ~14:00 UT (7:00 am PDT) on October 5. Unless the peak comes early it will occur after sunrise for observers in the western US. The peak time suggests a nice, but short, shower may be visible across the northern Pacific basin and in northeastern Asia. Since Camelopardalis is a far northern constellation, this shower is not visible from the Southern Hemisphere.

Draconids (Giacobinids) (GIA)

The Draconids have produced some of the highest rates of meteor activity in history. In both 1933 and 1946 rates were greater than 10,000 meteors per hour. Impressive rates of greater than 500 meteors per hour were also observed in 1952, 1985 and 1998. Unfortunately, this shower barely produces any meteors in non-storm years. What will this year hold in store? There are no predictions for any enhanced activity this year but we won’t know for sure unless we watch. This is another shower only observable from the Northern Hemisphere. It radiates from the constellation of Draco.

The Draconids are also known as the Giacobinids because they are produced by Comet 21P/Giacobini-Zinner. This comet was discovered by the same late 19th/early 20th century astronomer who found the recently re-discovered Comet 205P/Giacobini.

Epsilon Geminids (EGE)

This is an early morning shower which radiates from the constellation Gemini. It is visible between Oct 5 and 22 with a peak on Oct 14. At its best, only about 2 meteors per hour are visible.

Leo Minorids(LEO)

Yet another early morning shower, this time radiating from Leo Minor, a faint constellation just north of Leo. It is visible between Oct 17 and 27 with a maximum rate of only ~2 meteors per hour occurring on Oct 24.

Additional information on these showers and other minor showers not included here can be found at the following sites: Robert Lunsford’s Meteor Activity Outlook, Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2008 Meteor Shower Calendar.

Comets

Naked Eye Comets

There are no comets bright enough to be seen without binoculars or a telescope.

Binocular Comets

Comet C/2008 A1 (McNaught)

Comet McNaught is a long-period comet that will pass closest to the Sun on Sept 29 at a distance of 1.07 AU (100 million miles or 160 million km). It was the first comet discovered in 2008 having been found by  Robert McNaught of the Siding Spring Survey back on Jan 10. It was McNaught’s 43rd comet discovery.

Since discovery this comet could only be seen from the Southern Hemisphere. This month it moves rapidly to the north and is easily visible from the Northern Hemisphere by mid-month. During October, the comet travels through the constellations of Libra and Ophiuchus. The comet is as bright as it is going to get at magnitude 6.5. A comet of this brightness can be seen in binoculars or a small telescope.

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

Small Telescope Comets

Comet 6P/d’Arrest

Comet 6P/d’Arrest was one of the first short-period comets to be observed. First seen by the Frenchman Philippe de la Hire in 1678, the comet was definitively discovered by Heinrich Louis d’Arrest of Germany on 1851 June 28.

Comet d’Arrest is in a short-period orbit with a period of 6.5 years. It passed closest to the Sun back on Aug 14 at a distance of 1.35 AU (125 million miles or 200 million km). Comet d’Arrest starts the month in the southern constellation of Grus before entering Sculptor near months end. The comet is a very difficult object for observers in the Northern Hemisphere. With a brightness of magnitude 8.5 it will require a telescope to be seen though observers at very dark sites may be able to see it in binoculars.

A finder chart for Comet d’Arrest 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

(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 the surface. Ceres is one of two targets for NASA’s Dawn spacecraft which is scheduled to visit it in 2015. This month Ceres is located low in the eastern sky right before sunrise in Leo at magnitude 8.7.

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

(2) Pallas

Pallas is also a carbonaceous asteroid though with a slightly bluish B-type spectrum. Due to its high inclination (tilt of its orbit with respect to Earth’s orbit) of 34 degrees it is a difficult target for future spacecraft missions. Pallas is large with dimensions of 350x334x301 miles or 582x556x501 km. This month it is located in the southern constellation of Lepus and brightens from magnitude 8.7 to 8.2 over the course of the month.

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

(4) Vesta

Though not as large as Ceres, Vesta is more reflective making it the brightest asteroid in the Main Belt. Vesta is 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 is similar in size to Pallas with dimensions of 347x336x275 miles or 578×560×458 km. Vesta will also be visited by NASA’s Dawn spacecraft which will arrive in 2010. This month it is located in Cetus and brightens from magnitude 6.9 to 6.4 over the course of the month.

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

(9) Metis

Metis was discovered in 1848 by Andrew Graham of Ireland. It is a S-type asteroid with a composition similar to stony meteorites (ordinary chondrites). With a diameter of 140x120x85 miles or 235×195×140 km, it is much smaller than Ceres, Pallas or Vesta. In October Metis is located in Aries only a few degrees north of Vesta. It brightens from magnitude 9.4 to 8.6.

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

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