Comet ISON Sprouts a Double Tail

Today’s guest post is written by John Moffitt, Astrophysicist & HMNS Volunteer.

Amateur astronomers are getting a better look at Comet ISON as it dives toward the sun for a Nov. 28th close encounter with solar fire. As the heat rises, the comet brightens, revealing new details every day. This photo, taken Nov. 10th by Michael Jäger of Jauerling Austria, shows a beautiful double tail. One tail is the ion tail. It is a thin streamer of ionized gas pushed away from the comet by solar wind. The filamentary ion tail points almost directly away from the sun.

Comet Ison gets a double tail - 111013 - crop

The other tail is the dust tail. Like Hansel and Gretel leaving bread crumbs to mark their way through the forest, ISON is leaving a trail of comet dust as it moves through the solar system. Compared to the lightweight molecules in the ion tail, grains of comet dust are heavier and harder for solar wind to push around. The dust tends to stay where it is dropped. The dust tail, therefore, traces the comet’s orbit and does not point directly away from the sun as the ion tail does.

Comet ISON is currently moving through the constellation Virgo low in the eastern sky before dawn. Shining like an 8th magnitude star, it is still too dim for naked eye viewing, but an increasingly easy target for backyard optics. Amateur astronomers, if you have a GOTO telescope, enter these coordinates.

Four comets visible in the pre-dawn eastern sky. Look with binoculars before the sun comes up.

4 comets skymap - 111213

Comet ISON Briefings at HMNS

November 29 – December 1

To find out whether Comet ISON survives its close encounter with the Sun and how to see it in December’s morning sky, come to the Burke Baker Planetarium Friday through Sunday of Thanksgiving weekend. An ISON update will precede each Planetarium show!
PLANETARIUM LECTURE
“Tracking Comet ISON and Other Possible IMPACTS”
Thursday, December 5, 6 p.m.
Tickets $18, Members $12
Comets and asteroids that roam the inner solar system and are a possible threat to Earth. Comet ISON will be grazing the Sun on November 28, and if it survives, it may come within our view. Dr. Sumners will give an update on Comet ISON and other incoming objects. Includes viewing of the show Impact!

Click here for tickets and more information on the Comet ISON briefings.

Plunge 4,000 feet deep from your seat at Nautilus Live this week — it’s shipwreck time

Beginning last Wednesday, July 17 through this Thursday, July 25, the Nautilus and her two ROVs, Hercules and Argus, will be exploring a shipwreck located in the Gulf of Mexico. The wreckage site was discovered by Shell Oil while scanning a lease location. Because the ship has not yet been identified, it is being called the “Monterrey Shipwreck,” after Shell’s name for their proposed project.

The site will be the deepest shipwreck to be systematically investigated in the Gulf of Mexico. Due to its depth, the wreckage cannot be explored through usual means (through the use of SCUBA teams).

That is where Hercules and Argus come in. A team of scientists will be able to safely view and analyze the site from the Nautilus as it bobs more than 4,000 feet above the actual wreckage.

Nautilus Live

This particular shipwreck is referred to as “time capsule” wreckage. The ship is suggested to be extremely well preserved due to how deep it is and the lack of nearby oil and gas infrastructure. Using sonar data, the site appears to be tightly contained and an outline of a hull that is 84 feet long and 26 feet wide can be seen.

The goal of this project is to thoroughly map and document the wreck site while also recovering artifacts for analysis and exhibition. The team on the Nautilus is hoping to answer several questions about the wreckage: What is it? Whose ship was it? Why was it out on those particular waters? How was it lost? What caused it to sink? All of these answers may rewrite history and clarify forgotten events in the history of the Gulf of Mexico.

As exciting as studying a newly discovered ship wreck might be, the adventures of the Nautilus as well as Hercules and Argus don’t stop there. Over the next several months, the Nautilus will be studying several fascinating underwater sites. This includes visiting the deepest point in the Caribbean and studying an underwater mountain. The research team will also work off the coast of Puerto Rico and analyze the site of a 7.2 underwater earthquake that caused a tsunami!

They will also be studying underwater volcanos, including Kick’ em Jenny, the most active and dangerous underwater volcano in the Caribbean Sea. Experience these findings with the team from the Nautilus live in the Burke Baker Planetarium here at the Houston Museum of Natural Science.

Be transported to the ocean floor each day at 1 and 3 p.m. via telepresence technology and rove the sea bottom, making discoveries and interacting live with the Nautilus research team. For more information on this exclusive partnership and to purchase tickets online, click here.

Seeing Stars with James Wooten: June 2013

Mercury and Venus are together in the west at dusk. Venus outshines everything but the Sun and Moon, so you can begin observing it during deep twilight. Once you’ve found Venus, look for the dimmer Mercury, which will be above Venus and a little to its left in early June. The crescent Moon is near the pair on June 10. After mid-month, we see Mercury reverse field and head back into the glare of the Sun.

Saturn is now an evening object, shining in the southeast at dusk. Although not as bright as Venus, it does outshine the stars around it, so you can’t miss it. Mars and Jupiter are out of sight on the far side of the Sun this month.

sky map june 2013

The Big Dipper is above the North Star, with its handle pointing up. From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica’ — those stars are in the south at dusk.  Leo the Lion, is high in the west at dusk.

Antares, brightest star of Scorpius, the Scorpion, is in the southeast, with the ‘teapot’ of Sagittarius rising behind it. The Summer Triangle has fully risen in the northeast. The stars of summer are here.

Moon Phases in June 2013:

New                                June 8, 10:58 a.m.
First Quarter                  June 16, 12:24 p.m.
Full                                 June 23, 6:33 a.m.
Last Quarter                  June 29, 11:54 p.m.

At 12:04 am on Friday, June 21, the Sun is directly overhead at the Tropic of Cancer, the farthest point north at which the Sun can be overhead. This is therefore the summer solstice. On this date, those of us north of the equator enjoy more daylight and less night than on any other date of the year. In the Southern Hemisphere, folks experience the longest night and the shortest day, and the season is winter.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement. I generally do one such tour on short May nights.

To enjoy the stars in any weather from the comfort of the HMNS Planetarium, click here for a full schedule.

Seeing Stars with James Wooten: May 2013

Jupiter is now lower in the west at dusk. Face west at dusk and look for the brightest thing there (unless the Moon is also there), as Jupiter outshines all other stars we ever see at night. It appears slightly lower in the sky each night, though, and is gone by the end of the month. As Jupiter leaves the evening sky, Mercury and Venus emerge to join it on Memorial Day weekend. The three planets form a tight triangle May 25-26; Venus and Jupiter are just one degree apart on May 27.

Saturn is now an evening object, shining in the southeast at dusk.  Although not as bright as Jupiter, it does outshine the stars around it, so you can’t miss it.

Mars is still out of sight on the far side of the Sun this month.

Sky Map: May 2013A swath of brilliant winter stars sets in the west at dusk. Orion, the Hunter, is still visible in the west as May begins. His two dogs, represented by Sirius and Procyon, are to his left.  To Orion’s right is Taurus, the Bull, with Aldebaran as its eye. Gemini, the Twins, are above Orion. The Big Dipper is above the North Star, with its handle pointing to the right. From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica’; those stars are in the east and southeast at dusk. Leo, the Lion, passes almost overhead in late evening.

As Orion and Taurus set, look for Antares, brightest star of Scorpius, the Scorpion, to rise in the southeast. At the same time, Vega, brightest star of the Summer Triangle, appears low in the northeast. These stars remind us that summer is on the way.

Moon Phases in May 2013:

Last Quarter                 May 2, 6:16 am; May 31, 1:59 pm
New                              May 9, 7:31 pm
1st Quarter                   May 17, 11:35 pm
Full                                May 24, 11:26 pm

The New Moon of May 9 passes in front of the Sun, causing an eclipse. However, the Moon is too far from the Sun to block it completely; the result is an annular eclipse, in which a ring of the Sun’s disk surrounds the Moon. Also, the event is visible only along a path that begins in Australia and extends across the Pacific.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement. I generally do one such tour on short May nights.

To enjoy the stars in any weather from the comfort of the HMNS Planetarium, click here for a full schedule.