Tomorrow morning, December 10th, you will find a nice lineup of planets in the dawn sky. Mercury, Venus and Saturn will be in a line about 20° long. Adding to the lineup will be a nice crescent Moon, a bit over 10° higher in the sky than Saturn.
The view at 06:00HST will find a 19% illuminated Moon at 38° elevation. Working down the line you will see Saturn at 29° elevation, Venus at 15° elevation and Mercury at 9° elevation. With sunrise not until 06:46HST this will give plenty of time to view, and perhaps photograph, a line of planets in the dawn.
Over the next few days the view will be much the same, with the Moon lower each morning. On December 11th the Moon will sit between Venus and Mercury creating a nice trio.
Full Moon taken 27Aug2007, 90mm f/12 APO and Canon 20DaFull Moon will occur today at 04:46HST.
A penumbral lunar eclipse will be visible from western North America, across the Pacific to much of Asia. This is a fairly minor eclipse, with the Moon passing through the outer penumbral shadow of the Earth. A careful observer will note the light of the full Moon dimmed. As the Moon will not enter the darker umbral shadow the effects of this eclipse will not be obvious.
Tonight the Moon will be about 7° away from Jupiter, a bright pair rising together in the eastern sky after sunset. Tomorrow, November 28th, will see the Moon east of Jupiter, but even closer, just under 5° away.
A thin crescent Moon will be about 5.5° from Mars tonight. The Moon will be a thin crescent, only 8% illuminated. The pair will be about the same elevation, 25° above the horizon at sunset.
A very young moon over Waikoloa, this is only 26 hours after new, visible to the unaided eye as a sliver in the fading glow of sunsetNew Moon will occur today at 12:08HST.
During this new moon a total solar eclipse will sweep across Northern Australia and the South Pacific, ending before reaching the west coast of South America. None of this eclipse will be visible from Hawai’i.
Tomorrow morning, November 12th, Saturn will join a very thin Moon in the dawn. The pair will be at about the same elevation, 15° above the horizon at sunrise and about 4.5° apart. The Moon will be very thin, only 2.3% illuminated. Above the pair a brilliant Venus will shine at about 30° elevation at sunrise.
A thin crescent Moon will rise in accompaniment with Venus tomorrow morning. A brilliant Venus, shining at -4.0 magnitude, will rise about 5.5° from a 7% illuminated Moon. The pair will rise about 04:10HST and be about 30° above the horizon at sunrise.
Watching active volcanic eruptions should be done from a safe distance, and a group of California researchers has figured out how to do it from, ironically, Mauna Kea – one of Earth’s tallest volcanoes – using the W. M. Keck Observatory. Employing an ingenious combination of telescopic surveys and archival data, they have gathered nearly 40 distinct snapshots of effusive (slow) volcanic eruptions and high temperature outbursts on Jupiter’s tiny moon, Io, showing details as small as 100 km (60 miles) on the moon’s surface.
While space-based telescopes were once required for viewing surface details on Io – similar in size to our Moon, but more than 1,600 times distant – adaptive optics (AO), pioneered at Keck, allows teams like that led by Franck Marchis, a researcher at the Carl Sagan Center of the SETI Institute, to collect fascinating data on the wild show from Earth. Marchis presented results from ground-based telescopic monitoring of Io’s volcanic activity over the past decade this week, at the 2012 Division of Planetary Sciences Meeting of the American Astronomical Society.
Erupting volcanoes on Io cannot be seen well from beneath the Earth’s atmosphere using classical astronomical techniques. Io is a relatively small satellite with a 3,600 km diameter, more than 630 million kilometers away. In 1979, Voyager 1 visited the Jovian system, revealing Io’s dynamic volcanic activity from the first close-up pictures of its surface, capturing bizarre volcanic terrains, active plumes and hot spots. The Galileo spacecraft remained in orbit in the Jovian system from 1995 to 2003 and observed more than 160 active volcanoes and a broad range of eruption styles. Several outstanding questions remained in the post-Galileo era, and the origin and long-term evolution of Io’s volcanic activity is still not fully understood.
Quiescent activity of Io observed in 2010 and 2011 showing several quasi-permanent eruptions at 3.8 microns [bottom] and the absence of bright, hotter outbursts at 2.1 microns [top]. Credit: Franck Marchis, SETI Institute
In the meantime, astronomers designed instruments to break the “seeing barrier” and improve the image quality of ground-based telescopes. The blurring (“seeing”) introduced by the constant motion of the Earth’s atmosphere can be measured and corrected in real time using adaptive optics (AO), providing an image with a resolution close to the theoretical “diffraction limit” of the telescope. The W. M. Keck Observatory has used adaptive optics since 1999.
“Since our first observation of Io in 2001 using the Keck II 10-meter telescope and its AO system from Mauna Kea in Hawaii, our group became very excited about the technology. We also began using AO at the Very Large Telescope in Chile, and at the Gemini North telescope in Hawaii. The technology has improved over the years, and the image quality and usefulness of these AO systems have made them part of the essential instrument suite for large telescopes,” said Marchis.
