SpaceX to Launch 64 Satellites, Including Orbital Reflector

orbital Reflector
An artist’s impression of Orbital Reflector unfurled in space. Credit: Orbital Reflector/Nevada Museum of Art

UPDATE – SpaceX has now set a firm date and time for the Spaceflight SSO-A launch from Vandenberg Air Force Base for Monday, December 3nd at 18:31 Universal Time (UT).

A unique smallsat mission promises to be the latest satellite “brighter than a Full Moon!” in the night sky… or not.

The Mission: We’re talking about Orbital Reflector, conceived by Trevor Paglen and fielded by the Nevada Museum of Arts. Dubbed as the “first art exhibit in space,” the $1.3 million dollar project seeks to put a smallsat payload with a deployable reflector in low Earth orbit. Continue reading “SpaceX to Launch 64 Satellites, Including Orbital Reflector”

New Comet V1 Machholz-Fujikawa-Iwamoto Takes Observers by Surprise

Comet V1 Machholz

You just never know when it comes to comets. Here it is mid-November, and we’d thought we had finished up writing about bright comets for 2018. That was until this past weekend, when a flurry of messages flashed across the Yahoo! Comets mailing list hinting that a new, possibly bright comet had been discovered. Come Monday morning November 12th, long period Comet C/2018 V1 Machholz-Fujikawa-Iwamoto was formally added to the International Astronomical Union’s Minor Planet list.
Continue reading “New Comet V1 Machholz-Fujikawa-Iwamoto Takes Observers by Surprise”

Scientists are Using Artificial Intelligence to See Inside Stars Using Sound Waves

NASA's Solar Dynamics Observatory has captured images of a growing dark region on the surface of the Sun. Called a coronal hole, it produces high-speed solar winds that can disrupt satellite communications. Image: Solar Dynamics Observatory / NASA

How in the world could you possibly look inside a star? You could break out the scalpels and other tools of the surgical trade, but good luck getting within a few million kilometers of the surface before your skin melts off. The stars of our universe hide their secrets very well, but astronomers can outmatch their cleverness and have found ways to peer into their hearts using, of all things, sound waves. Continue reading “Scientists are Using Artificial Intelligence to See Inside Stars Using Sound Waves”

How Mission Delays Hurt Young Astronomers

Back in Ye Olden Times, the job of astronomer was a pretty exclusive club. Either you needed to be so rich and so bored that you could design, build, and operate your own private observatory, or you needed to have a rich and bored friend who could finance your cosmic curiosity for you. By contrast, today’s modern observatories are much more democratic, offering of a wealth of juicy scientific info for researchers across the globe. But that ease of access comes with its own price: you don’t get the instrument all to yourself, and that’s a challenge for young scientists and their research.

Continue reading “How Mission Delays Hurt Young Astronomers”

Exploring the Ice Giants: Neptune and Uranus at Opposition for 2018

The existence of Neptune was inferred by its gravitational effect on other bodies long before it was ever observed. Image Credi: NASA/JPL

Have you seen the outer ice giant planets for yourself?

This week is a good time to check the most difficult of the major planets off of your life list, as Neptune reaches opposition for 2018 on Friday, September 7th at at ~18:00 Universal Time (UT)/2:00 PM EDT. And while it may not look like much more than a gray-blue dot at the eyepiece, the outermost ice giant world has a fascinating tale to tell. Continue reading “Exploring the Ice Giants: Neptune and Uranus at Opposition for 2018”

Catch Comet 21/P Giacobini-Zinner at Its Best

Comet 21/P Giacobini-Zinner from August 14th. Image credit and copyright: Rolando Ligustri.

A periodic comet may put on a fine show for northern hemisphere viewers over the next few months.

Comet 21/P Giacobini-Zinner is currently a fine binocular comet, shining at +8th magnitude as it cruises across the constellation Cassiopeia. This places it above the horizon for the entire night for observers north of the equator in August, transiting the local meridian at dawn. And unlike most comets that get lost in the Sun’s glare (like the current situation with C/2017 S3 PanSTARRS), we’ll be able to track Comet 21/P Giacobini-Zinner right through perihelion on September 10th.

The orbit of comet 21P, showing the comet’s position at closest approach. Credit: NASA-JPL.

This is because the comet is on a short period, 6.6 year orbit around the Sun that takes it from an aphelion of 6 Astronomical Units (AU) exterior to Jupiter’s orbit, to a perihelion of 1.038 AU, just 3.3 million miles (5.2 million kilometers) exterior to Earth’s orbit. The 2018 apparition sees the comet pass 0.392 AU (36.5 million miles/58.3 million kilometers) from the Earth on September 11th.

This is the closest passage of the comet near Earth since September 14th, 1946, and won’t be topped until the perihelion passage of September 18th, 2058. Its next cycle of passes to Earth closer than 0.1 AU aren’t until next century in the years 2119 and 2195, respectively.

Comet 21/P from August 10th. Image credit and copyright: John Purvis.

Discovered by astronomer Michel Giacobini at the Côte d’Azur Observatory in Nice, France on the night of December 20th, 1900 as it was crossing the constellation Aquarius, the 21st periodic comet was recovered two orbits later by Ernest Zinner on October 23rd, 1913 as it passed a series of variable stars near Beta Scuti.

Though the comet generally tops out at +8th magnitude, it has been known to undergo periodic outbursts near perihelion, bringing it up about 3 magnitudes (about 16 times) in brightness. This occurred most notably in 1946.

The light curve for Comet 21/P. The black dots represent actual observations and magnitude observations. Credit: Seiichi Yoshida’s Weekly Information on Bright Comets.

Comet 21/P Giacobini-Zinner is also the source of the Draconid (sometimes referred to as the Giacobinid) meteors, radiating from the constellation Draco the Dragon on and around October 7th and 8th. Feeble on most years, this shower can produce surprises, such as occurred in 1998, 2005 and most recently in 2011, when a Draconid outburst topped a zenithal hourly rate of 400 meteors per hour, flirting with ‘meteor storm’ status. And while we’re not expecting a meteor storm to accompany the 2018 perihelion passage of Comet 21/P Giacobini-Zinner, you just never know… it’s always worth keeping an eye out on early October mornings for the “Tears of the Dragon,” just in case. Note that the Moon reaches New phase on October 9th, just a few days after the meteor shower’s expected annual peak, a fine time to watch for any unheralded Draconid outbursts.

Prospects for Comet 21P

The comet is visible from the northern hemisphere through the remainder of August and all through September as it glides across Auriga, Taurus and Gemini and visits several well known celestial sights. In fact, it actually transits in front of several deep sky objects, including Messier 37 (Sept 10th), and Messier 35 (Sept 15th).

Comet 21P passes in front of open cluster Messier 35 on September 15th. Credit: Starry Night.

The comet will be moving at about two degrees per day when it’s nearest to the Earth, on and around September 11th.

We begin to lose the comet, as it heads southward in late October. Still, the comet is over 50 degrees above the eastern horizon at dawn come October 1st as seen from latitude 30 degrees north, having maintained a similar elevation throughout most of September. Not bad at all.

Here are some upcoming dates with destiny for Comet 21/P Giacobini-Zinner:

August 19: Crosses into the constellation Camelopardalis.

August 29: Crosses into the constellation Perseus.

August 30th: Crosses into the constellation Auriga.

The celestial path of Comet 21P from August 16th through September 15th. Credit: Starry Night.

September 2: Passes one degree from the bright star Capella.

Sept 7-8: Grouped 2 degrees from the open clusters M36 and M38.

Sept 10: Photo-Op: Skirts very near the open cluster M37. Also reaches perihelion on this date, at magnitude +7.

Sept 11: Passes closest to the Earth, at 0.392 AU distant.

Sept 13: Nicks the corner of the constellation Taurus.

Sept 14th : Enters the constellation Gemini.

Sept 15th: Photo-Op: crosses in front of the open cluster M35.

Sept 16: Crosses the ecliptic southward and near the +3.3 magnitude star Propus (Eta Geminorum).

Sept 17: Crosses into Orion.

Sept 21: Crosses into Gemini.

Sept 23: Crosses into Monoceros.

Sept 24: Passes near the Christmas Tree Cluster, NGC 2264.

The celestial path of Comet 21P from September 15th through October 15th. Image credit: Starry Night.

Oct 1: Crosses the galactic plane and the celestial equator southward.

Oct 7: Crosses in front of the open cluster M50.

Oct 10: Crosses into Canis Major.

Oct 31st: Passes near the bright star Aludra and may drop below +10th magnitude.

Binoculars are your best friend when you’re looking for comets brighter than +10th magnitude. With a generous field of view, binoculars allow you to sweep a suspect area until the faint fuzzball of a comet snaps into view. I like to ‘ambush’ a comet as it passes near a bright star, and a good time to spot comet 21/P Giacobini-Zinner is coming right up on September 2nd when it passes less than one degree from the bright +0.1 magnitude star Capella.

Don’t miss this year’s fine apparition of Comet 21/P Giacobini-Zinner, coming to a night sky near you.