Category Archives: Events

Events, Multiple media

Space Advent Calendars

Check out these two holiday season advent calendars. They both will display a beautiful new space picture for each day till Christmas:

First day of The Atlantic calendar:

This year’s first image: A composite image of visible-light observations by
NASA’s Hubble Space Telescope, combined with infrared data from
the ground-based Large Binocular Telescope in Arizona to assemble a
dramatic view of the well-known Ring Nebula….continue

 

First day of the PhotoBlog/MSNBC calendar:

The Mars Color Camera for India’s Mars Orbiter Mission, also known as Mangalyaan,
captures an image of Africa, Arabia, India and other parts of Asia on Nov. 19
during its Earth-orbiting phase, from an altitude of
almost 43,500 miles (70,000 kilometers).

Asteroids & Comets, Astronomy, Events

The ISON story continues

The latest on comet ISON:

NASA Investigating the Life of Comet ISON

After several days of continued observations, scientists continue to work to determine and to understand the fate of Comet ISON: There’s no doubt that the comet shrank in size considerably as it rounded the sun and there’s no doubt that something made it out on the other side to shoot back into space. The question remains as to whether the bright spot seen moving away from the sun was simply debris, or whether a small nucleus of the original ball of ice was still there. Regardless, it is likely that it is now only dust.

Comet ISON comes in from the bottom right and moves out toward the upper right, getting fainter and fainter.
Comet ISON comes in from the bottom right and moves out toward the upper right, getting fainter and fainter, in this time-lapse image from the ESA/NASA Solar and Heliospheric Observatory. The image of the sun at the center is from NASA’s Solar Dynamics Observatory. Image Credit: ESA/NASA/SOHO/SDO/GSFC

Comet ISON, which began its journey from the Oort Cloud some 3 million years ago, made its closest approach to the sun on Nov. 28, 2013. The comet was visible in instruments on NASA’s Solar Terrestrial Relations Observatory, or STEREO, and the joint European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, via images called coronagraphs. Coronagraphs block out the sun and a considerable distance around it, in order to better observe the dim structures in the sun’s atmosphere, the corona. As such, there was a period of several hours when the comet was obscured in these images, blocked from view along with the sun. During this period of time, NASA’s Solar Dynamics Observatory could not see the comet, leading many scientists to surmise that the comet had disintegrated completely. However, something did reappear in SOHO and STEREO coronagraphs some time later – though it was significantly less bright.

http://youtu.be/kcROVqmF9SY
Comet ISON is shown approaching the sun and curving away from it in this movie containing imagery from both NASA’s Solar Terrestrial Relations Observatory and the joint ESA/NASA Solar and Heliospheric Observatory from November 2013. ISON dims dramatically as it streams away from the sun.
Image Credit: ESA/NASA/SOHO/STEREO/GSFC

Whether that spot of light was merely a cloud of dust that once was a comet, or if it still had a nucleus – a small ball of its original, icy material – intact, is still unclear. It seems likely that as of Dec. 1, there was no nucleus left. By monitoring its changes in brightness over time, scientists can estimate whether there’s a nucleus or not, but our best chance at knowing for sure will be if the Hubble Space Telescope makes observations later in December 2013.

Regardless of its fate, Comet ISON did not disappoint researchers. Over the last year, observatories around the world and in space gathered one of the largest sets of comet observations of all time, which should provide fodder for study for years to come. The number of space-based, ground-based, and amateur observations were unprecedented, with twelve NASA space-based assets observing over the past year.

Related Links:

For more information on Comet ISON: www.nasa.gov/ison

To download recent ISON imagery: http://svs.gsfc.nasa.gov/Gallery/CometISON.html

Astronomy, Events, Solar Science

ISON – The die hard comet

4 Comments

Evidence is growing that a part of the Comet ISON nucleus did in fact survive its close solar experience (see previous posting). Here is a report from NASA:

Comet ISON May Have Survived

Continuing a history of surprising behavior, material from Comet ISON appeared on the other side of the sun on the evening on Nov. 28, 2013, despite not having been seen in observations during its closest approach to the sun.

This movie shows Comet ISON orbiting around the sun – represented by the white
circle — on Nov. 28, 2013. ISON looks smaller as it streams away, but scientists
believe its nucleus may still be intact. The video covers Nov. 27, 2013, 3:30 p.m. ET
to Nov. 29, 2013, 8:30 a.m. ET. Image Credit: ESA/NASA/SOHO/Jhelioviewer

As ISON appeared to dim and fizzle in several observatories and later could not be seen at all by NASA’s Solar Dynamics Observatory or by ground based solar observatories, many scientists believed it had disintegrated completely. However, a streak of bright material streaming away from the sun appeared in the European Space Agency and NASA’s Solar and Heliospheric Observatory later in the evening. The question remains whether it is merely debris from the comet, or if some portion of the comet’s nucleus survived, but late-night analysis from scientists with NASA’s Comet ISON Observing Campaign suggest that there is at least a small nucleus intact.

Three view of what's left of Comet ISON rounding the sun.
ISON appears as a white smear heading up and away from the sun. ISON was
not visible during its closest approach to the sun, so many scientists thought
it had disintegrated, but images like this one from the ESA/NASA Solar and
Heliospheric Observatory suggest that a small nucleus may be intact.
Image Credit: ESA/NASA/SOHO/GSFC
Continuing a history of surprising behavior, material from Comet ISON appeared on the other side of the sun on the evening on Nov. 28, 2013, despite not having been seen in observations during its closest approach to the sun.

As ISON appeared to dim and fizzle in several observatories and later could not be seen at all by NASA’s Solar Dynamics Observatory or by ground based solar observatories, many scientists believed it had disintegrated completely. However, a streak of bright material streaming away from the sun appeared in the European Space Agency and NASA’s Solar and Heliospheric Observatory later in the evening. The question remains whether it is merely debris from the comet, or if some portion of the comet’s nucleus survived, but late-night analysis from scientists with NASA’s Comet ISON Observing Campaign suggest that there is at least a small nucleus intact.

A bright ISON goes into the sun, a dim ISON comes out.
Another view from SOHO’s C2 chronograph shows Comet ISON appearing
bright as it streams toward the sun (right). it can be seen as a dim streak
heading upward and out in the left image. The comet may still be intact.
Image Credit: ESA/NASA/SOHO/Jhelioviewer

Throughout the year that researchers have watched Comet ISON – and especially during its final approach to the sun – the comet brightened and dimmed in unexpected ways.  Such brightness changes usually occur in response to material boiling off the comet, and different material will do so at different temperatures thus providing clues as to what the comet is made of.  Analyzing this pattern will help scientists understand the composition of ISON, which contains material assembled during the very formation of the solar system some 4.5 billion years ago.

Related Links:

For more information on Comet ISON: www.nasa.gov/ison

To download recent ISON imagery: http://svs.gsfc.nasa.gov/Gallery/CometISON.html

Astronomy, Events, Solar Science

Comet ISON swings around the sun [Update]

The Comet ISON  swung behind the Sun today. Initial reports were that it did not survive its close encounter with the big heat but others are now saying that there appears to be a small object that remains on the same trajectory. Will watch for updates.

[ Update 1:10 am Nov.29.13: It’s still unclear as to whether there is a substantial remnant of the ISON core remaining after the comet’s encounter with the sun or if there is just a fading dust cloud:

]

Here’s are some great images of  ISON taken from the SOHO spacecraft before it went around the sun:  Comet ISON Streams Toward the Sun – NASA

ISON approaches the Sun as seen from SOHO LASCO C3 (Nov 28, 2013)

NASA / ESA / SOHO / Emily Lakdawalla
ISON approaches the Sun as seen from SOHO LASCO C3 (Nov 28, 2013)

This animation contains 123 images captured by the SOHO spacecraft between November 26 at 21:20 UT and November 28 at 15:37 UT.

Comet ISON Streams Toward the Sun

 

Comet ISON moves ever closer to the sun in this image from ESA and NASA's Solar and Heliospheric Observatory captured at 9:30 a.m. EST on Nov. 28, 2013.

Latest updates at

Astronomy, Events, Multiple media

Comet ISON update – Swinging around the sun, Images from NASA spacecraft, and more

As mentioned earlier, Comet ISON has brightened considerably as it has gotten closer to the sun. It will go behind the sun on November 28th and there is great interest in how the comet will be affected by this closest encounter to the sun’s intense heat.

Don Yeomans, manager of NASA’s Near-Earth Object Program talks about Comet ISON and what might happened to it when it emerges from around the sun:

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NASA’s MESSENGER spacecraft orbiting Mercury and the STEREO solar science probes have returned images of the comet.

Here’s an image of ISON from MESSENGER:

figure2_messenger_ison[1]

 

Here’s a GIF animation of images from the STEREO showing not only ISON but also Comet Encke:

NASA’s STEREO-A spacecraft is monitoring Comet ISON as it approaches the sun.
The latest movie from the spacecraft’s Heliospheric Imager shows Comet ISON,
Mercury, Comet Encke and Earth over a two day period from Nov. 20 to Nov. 22, 2013.
The sun sits right of the field of view of this camera.
Image Credit:  Karl Battams/NRL/NASA STEREO/CIOC.

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Lots of great pictures made by amateur astronomers can be found at  Spaceweather.com Realtime Image Gallery

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More info on ISON:

 

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