Monthly Archives: September 2015

Future space, Space Systems, Speculation

Starship Congress 2015: Interstellar Hackathon – live feed available

The Starship Congress 2015: Interstellar Hackathon is underway today and tomorrow at Drexel University. Videos from the event, including a live feed,  are available at the Icarus Interstellar YouTube channel. See the presentation schedule here.

Organized by the Icarus Interstellar group, the event is described as follows:

Starship Congress is the not-for-profit science organization’s biennial international assemblage of recognized interstellar-and-deep space scientists and proponents. The 2nd Starship Congress will be hosted at Drexel University this September 4-5.

With a nod to this year’s University setting and a Hollywood and video game-driven surge in popularity of deep space exploration (“Interstellar”, “Guardians of the Galaxy”, “EVE: Valkyrie”, “Kerbal Space Program 1.0”), Starship Congress 2015 is being subtitled Interstellar Hackathon—featuring talks and presentations centered on hacking the paradigm of interstellar space exploration. Events leading up to the September summit include academic paper submission, poster contest and crowdfunded Kickstarter campaign. Drexel University is home to the first collegiate chapter of Icarus Interstellar.

Starship Congress 2015: Interstellar Hackathon will be built around workshops and punctuated by speakers from the deep space science community over the two-day event. Icarus Interstellar welcomes paper presentation by representatives of aerospace, aeronautics, advanced materials, fission and fusion research fields. Registration for Starship Congress 2015 will open later this week on Icarus Interstellar’s website. A call-for-papers will also be made in May. (Preliminary schedule for the 2-day event is included here below.)

“Two personal reasons for being involved in interstellar studies: Its the most fun and the most significant achievement humanity has undertaken”, notes Dr. Andreas Tziolas, president of Icarus Interstellar. “Icarus’ role is to keep up the pressure by coordinating cutting edge research in a way which is approachable and understandable to everyone seeking to participate. This first ever, Interstellar Hackathon will be as fun as it will be productive, as we challenge participants to think fast and hard about exploring our place in the universe.”

As before, Starship Congress aims to bring the interstellar and deep space science community together in order to foster discussion and generate tangible action. Distinct from the first Starship Congress, the 2015 edition is being structured to quickly break-down status quo approaches in anticipation of reaping new results from looking at old challenges with fresh outlooks.

“Just pulling off Starship Congress 2013 with so many important scientists and thinkers working together was an incredible experience,” says Starship Congress strategic director Mike Mongo, “and one that reaped qualifiable advances in thinking about interstellar space exploration. I am boggling just imagining how that effect will be furthered by Starship Congress 2015’s being staged on a notable university campus like Drexel. We are hacking Starship Congress itself by introducing the benefits and influences of an acclaimed academic setting.”

…

Starship Congress is the premier assemblage of international interstellar proponents and advocacy groups united in the common goal of deep space and interstellar accomplishment. By combining presentation, discussion, and decision, Starship Congress aims to engender and reach consensus of actionable items throughout the interstellar community.

Icarus Interstellar is dedicated to promoting the dream of interstellar flight, a dream springing from the same kernel of Boldness found in the original vision of humans taking flight. Founded as an organization in 2009, Icarus Interstellar became a 501c3 non-for-profit registered in the state of Alaska in 2011.

 

 

Exoplanets, SETI

Video: Latest on occurrence rates of earth-like exoplanets

Here’s a SETI Institute seminar on using the Kepler space observatory data to determine how often earth-like exoplanets will be found around other stars: Planet Occurrence Rates with Kepler: Reaching Towards the Habitable Zone – SETI Institute

Dr. [Christopher Burke discusses the] latest results in measuring terrestrial planet occurrence rates using the planet candidates discovered by the Kepler pipeline.

For the first time an accurate model for the Kepler pipeline sensitivity to transiting planets is publicly available. Dr. Burke’s new analysis finds higher planet occurrence rates and a steeper increase in planet occurrence rates toward small planets than previously believed.

In addition, Dr. Burke will identify the leading sources of systematics that remain impacting Kepler planet occurrence rate determinations and approaches for minimizing their impact in future studies.

This work also sharpens our understanding on the dependence of planet occurrence rates on stellar effective temperature with potential implications for understanding the planet formation process.

Gas giants Saturn, Jupiter, et al, Space Science, Space Systems

Saturn: One of the rings is not like the others + An update on the Cassini mission

A report from the Cassini mission at Saturn:

PIA11667_500[1]

Cassini Solstice Mission: At Saturn, One of These Rings is not like the Others

At Saturn, One of These Rings is not like the Others

Fast Facts:
— A study suggests the particles in one section of Saturn’s rings are denser than elsewhere, possibly due to solid, icy cores.

— The findings could mean that particular ring is much younger than the rest.

When the sun set on Saturn’s rings in August 2009, scientists on NASA’s Cassini mission were watching closely. It was the equinox — one of two times in the Saturnian year when the sun illuminates the planet’s enormous ring system edge-on. The event provided an extraordinary opportunity for the orbiting Cassini spacecraft to observe short-lived changes in the rings that reveal details about their nature.

Like Earth, Saturn is tilted on its axis. Over the course of its 29-year-long orbit, the sun’s rays move from north to south over the planet and its rings, and back again. The changing sunlight causes the temperature of the rings — which are made of trillions of icy particles — to vary from season to season. During equinox, which lasted only a few days, unusual shadows and wavy structures appeared and, as they sat in twilight for this brief period, the rings began to cool.

In a recent study published in the journal Icarus, a team of Cassini scientists reported that one section of the rings appears to have been running a slight fever during equinox. The higher-than-expected temperature provided a unique window into the interior structure of ring particles not usually available to scientists.

“For the most part, we can’t learn much about what Saturn’s ring particles are like deeper than 1 millimeter below the surface. But the fact that one part of the rings didn’t cool as expected allowed us to model what they might be like on the inside,” said Ryuji Morishima of NASA’s Jet Propulsion Laboratory, Pasadena, California, who led the study.

The researchers examined data collected by Cassini’s Composite Infrared Spectrometer during the year around equinox. The instrument essentially took the rings’ temperature as they cooled. The scientists then compared the temperature data with computer models that attempt to describe the properties of ring particles on an individual scale.

What they found was puzzling. For most of the giant expanse of Saturn’s rings, the models correctly predicted how the rings cooled as they fell into darkness. But one large section — the outermost of the large, main rings, called the A ring — was much warmer than the models predicted. The temperature spike was especially prominent in the middle of the A ring.

To address this curiosity, Morishima and colleagues performed a detailed investigation of how ring particles with different structures would warm up and cool down during Saturn’s seasons. Previous studies based on Cassini data have shown Saturn’s icy ring particles are fluffy on the outside, like fresh snow. This outer material, called regolith, is created over time, as tiny impacts pulverize the surface of each particle. The team’s analysis suggested the best explanation for the A ring’s equinox temperatures was for the ring to be composed largely of particles roughly 3 feet (1 meter) wide made of mostly solid ice, with only a thin coating of regolith.

“A high concentration of dense, solid ice chunks in this one region of Saturn’s rings is unexpected,” said Morishima. “Ring particles usually spread out and become evenly distributed on a timescale of about 100 million years.”

The accumulation of dense ring particles in one place suggests that some process either placed the particles there in the recent geologic past or the particles are somehow being confined there. The researchers suggest a couple of possibilities to explain how this aggregation came to be. A moon may have existed at that location within the past hundred million years or so and was destroyed, perhaps by a giant impact. If so, debris from the breakup might not have had time to diffuse evenly throughout the ring. Alternatively, they posit that small, rubble-pile moonlets could be transporting the dense, icy particles as they migrate within the ring. The moonlets could disperse the icy chunks in the middle A ring as they break up there under the gravitational influence of Saturn and its larger moons.

“This particular result is fascinating because it suggests that the middle of Saturn’s A ring may be much younger than the rest of the rings,” said Linda Spilker, Cassini project scientist at JPL and a co-author of the study. “Other parts of the rings may be as old as Saturn itself.”

During its final series of close orbits to Saturn, Cassini will directly measure the mass of the planet’s main rings for the first time, using gravity science. Scientists will use the mass of the rings to place constraints on their age.

The Cassini-Huygens mission is a cooperative project of NASA, ESA and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate in Washington.

For more information about Cassini, visit:

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Check out also the recent discussion with Dr. Curt Niebur of NASA about Saturn and the Cassini mission: John Batchelor Hotel Mars, Wednesday, 8-26-15 | Thespaceshow’s Blog

Astronomy

ESO: New image of Prawn Nebula depicts “Cosmic Recycling”

The latest ESO (European Southern Observatory) report:

Cosmic Recycling

Dominating this image is part of the gigantic nebula Gum 56, illuminated by the hot bright young stars that were born within it. For millions of years stars have been created out of the gas in this nebula, material which is later returned to the stellar nursery when the aging stars either expel their material gently into space or eject it more dramatically as supernova explosions. This image was taken with the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile as part of ESO’s Cosmic Gems programme.

The rich patchwork of gas clouds in this new image make up part of a huge stellar nursery nicknamed the Prawn Nebula (also known as Gum 56 and IC 4628). Taken using the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile, this may well be one of the best pictures ever taken of this object. It shows clumps of hot new-born stars nestled in among the clouds that make up the nebula.
The rich patchwork of gas clouds in this new image make up part of a huge stellar nursery nicknamed the Prawn Nebula (also known as Gum 56 and IC 4628). Taken using the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile, this may well be one of the best pictures ever taken of this object. It shows clumps of hot new-born stars nestled in among the clouds that make up the nebula.

Deeply immersed in this huge stellar nursery are three clusters of hot young stars — only a few million years old — which glow brightly in ultraviolet light. It is the light from these stars that causes the nebula’s gas clouds to glow. The radiation strips electrons from atoms — a process known as ionisation — and when they recombine they release energy in the form of light. Each chemical element emits light in characteristic colours and the large clouds of hydrogen in the nebula are the cause of its rich red glow.

Gum 56 — also known as IC 4628 or by its nickname, the Prawn Nebula — is named after the Australian astronomer Colin Stanley Gum, who, in 1955, published a catalogue of H II regions. H II regions such as Gum 56 are huge, low density clouds containing a large amount of ionised hydrogen.

This video sequence starts with a view of the rich central parts of the Milky Way and then closes in on a spectacular region of star formation known as the Prawn Nebula (also known as Gum 56 and IC 4628) in the constellation of Scorpius (The Scorpion). The final close up view is a very sharp image taken using the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. Credit: ESO/Nick Risinger (skysurvey.org). Music: Johan B Monell

A large portion of the ionisation in Gum 56 is done by two O-type stars, which are hot blue–white stars, also known as blue giants because of their colour [1]. This type of star is rare in the Universe as the very large mass of blue giants means that they do not live for long. After only roughly a million years these stars will collapse in on themselves and end their lives as supernovae, as will many of the other massive stars within the nebula.

Besides the many newborn stars nestled in the nebula, this large region is still filled with enough dust and gas to create an even newer generation of stars. The regions of the nebula giving birth to new stars are visible in the image as dense clouds. The material forming these new stars includes the remains of the most massive stars from an older generation that have already ended their lives and ejected their material in violent supernova explosions. Thus the cycle of stellar life and death continues.

Given the two very unusual blue giants in this area and the prominence of the nebula at infrared and radio wavelengths, it is perhaps surprising that this region has been comparatively little studied as yet by professional astronomers. Gum 56 has a diameter of around 250 light-years, but despite its huge size it has also often been overlooked by visual observers due to its faintness, and because most of the light it emits is at wavelengths not visible to the human eye.

The nebula is at a distance of about 6000 light-years from Earth. In the sky it can be found in the constellation Scorpius (The Scorpion) where it has a projected size which is four times the size of the full Moon [2].

This image, which only captures a part of the nebula, was taken with the 2.2-metre MPG/ESO telescope using the Wide Field Imager (WFI) camera as part of the ESO Cosmic Gems programme. The programme makes use of telescope time that cannot be used for science observations to produce images of interesting, intriguing or visually attractive objects. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.

This chart shows the prominent constellation of Scorpius (The Scorpion). Most of the stars that can be seen in a dark sky with the unaided eye are marked. The location of the star formation region called the Prawn Nebula (IC 4628) is indicated with a red circle. This cloud appears large but is very faint and cannot be seen visually with a small telescope.
This chart shows the prominent constellation of Scorpius (The Scorpion). Most of the stars that can be seen in a dark sky with the unaided eye are marked. The location of the star formation region called the Prawn Nebula (IC 4628) is indicated with a red circle. This cloud appears large but is very faint and cannot be seen visually with a small telescope.

Notes

[1] Note that these stars fall outside the field of view of this particular image and do not appear in the picture.

[2] A wide-angle view of the Prawn Nebula taken by the VLT Survey Telescope was published earlier (eso1340a).