April 16, 2014

AstroEvent: Will Anyone Welcome the New Saros?

A Remote partial for the hardcore…(Credit: Eclipse Predictions by Fred Espenak, NASA/GSFC).

This week, we’d like to turn your attention to a unique event that no one but a few penguins may witness. July 1st kicks off the month with a partial eclipse of the Sun, the second solar in the past month and the third eclipse overall. The penumbra of the Moon will barely kiss the Earth from 07:53 to 9:22UT and greatest eclipse is a paltry 9.7% around 8:39UT. [Read more...]

10.05.11: It’s a CSA Tweetup!

CSA Astronaut Julie Payette aboard STS-127 (Credit: NASA/CSA).

A social media phenomenon has now spread beyond U.S. borders. Recently, the Canadian Space Agency has announced  that it will hold its first ever Tweetup May 13th at 10:00-11:30 AM EDT in conjunction with the unveiling of a new exhibit at the Canadian Aviation and Space Museum entitled Living in Space. The event may be tiny, with only 10 randomly selected participants plus guests, but trust me, as a veteran of two NASAtweetups, these are fun events to attend! Canadian astronauts will be on hand to answer questions, and the whole event will be carried live on the Canadian Space Agencies’ website. [Read more...]

18.02.11: A Titan(ic) Flyby.

Titan (Lower Left) paired with Saturn as seen from Cassini last year. (Credit: NASA/Cassini/JPL/The Space Science Institute).

Far out in the depths of the solar system, one of our most distant orbiting ambassadors is completing a flyby of the largest known moon. On Friday, February 18th at 11:04AM EST NASA’s Cassini orbiter will skim the Saturnian moon at a distance of just 2,270 miles above the enigmatic moon Titan. [Read more...]

14.02.11: Sol Unleashes A Powerful Radio Flare.

An SDO spectrum composite of the sun as of Monday, February 14th.  (Credit: NASA/SDO).

Our nearest star unleashed the most powerful solar flare of 2011 thus far yesterday, and amateur and professionals alike were on hand to bear witness to the event. On Sunday, February 13th at approximately 1738 Universal Time, NASA’s Solar Dynamics Observatory detected the burst emanating from the large Earthward facing sunspot group 1158. Likewise, radio amateur astronomers detected a large simultaneous spike in the 19 to 21 MHz frequency range. [Read more...]

09.02.11: A (Virtual) Martian Landing.

Preparing for Martian EVA…(Credit: ESA/IBMP/Mars 500).

Ever hoped man would walk on Mars in our lifetime? For the past eight months, a six man crew based in a simulated environment has been headed towards a mock up of just such an event. The program is none other than the Mars 500 mission, the European Space Agency’s (ESA) 500 day “voyage” to the planet Mars. On June 3rd, 2010, six volunteers sequestered themselves in an experimental facility at Moscow’s Institute for Bio-Medical Problems (IBMP) to take part in a study of the physiological and psychological impacts such a long mission would have. [Read more...]

27.01.11: A Surge of Sungrazers.


A January 2010 sungrazer. (Credit: ESA/SOHO).

A curious event closed out the year 2010. From December 13th to the 22nd, astronomers studying the Sun noticed an unprecedented upswing in the number of sun diving comets. In fact, researchers spied no less than 25 comets in ten days, a record rate. The data comes from the European Space Agencies (ESA) Solar Heliospheric Observatory (SOHO) which has stared at the sun since its launch in 1996. [Read more...]

10.06.10: Herschel Celebrates its 1st Year in Space.

TNO Makemake as imaged by Hershel's SPIRE camera. (Credit: ESA/Hershel/T. Mueller).

TNO Makemake as imaged by Hershel's SPIRE camera. (Credit: ESA/Hershel/T. Mueller).

 

    While everyone was celebrating Hubble’s 20th this past April, and equally amazing instrument past a quiet milestone: the European Space Agencies’ Herschel Space Observatory passed its first anniversary in space. On May 14, 2009, Herschel was launched as part of a dual payload along with the Planck spacecraft which is in the midst of mapping the cosmic microwave background. Sporting an 11.5 foot mirror (larger than HSTs) Herschel specializes in the far-infrared to submillimeter wavelengths of 55 to 670 microns. To this end, Herschel must be kept “on ice” and is placed at the L2 point in a Lissajous orbit to observe its infrared quarry. This also means that it is well beyond any hope of repair, which will also be the case for the James Webb Space telescope when it’s launched in 2014. An onboard supply of liquid helium keeps the detectors cooled down; cooling of the primary is completed by deployment of an enormous sunshade. Herschel sports three instruments: The PACS (the Photodetecting Array Camera and Spectrometer) and SPIRE (the Spectral and Photometric Imaging Receiver) cameras, and the on-again, off again ultra-high-precision spectrometer (HIFI, or the Heterodyne Instrument for the Far Infrared) detector. Herschel allows us to probe the “cold universe” in ways that would be impossible from the ground. Images such as the famous Horsehead Nebula in the far-infrared have given us key insight as to the inner workings of these dusty regions. In addition, studies have zeroed in on key star forming regions inaccessible from ground based telescopes, such as the enormous RCW 120 interstellar bubble 4,300 light years distant, which may one day collapse into an ultra-massive star. And that’s just the beginning… a proposed program known as ATLAS (the Astrophysical Terahertz Large Area Survey) may utilize Herschel’s capabilities to map a 550 square degree area (about 23.5 degrees on a side) of the sky at five wavelengths as a sort of “Herschel Deep Field” in the submillimeter. Such as task is expected to take up to 600 hours of exposures to complete and uncover perhaps a quarter million primordial galaxies at new wavelengths… Hershel is definitely a platform worth keeping tabs on!

16.05.10- Gliese 710: A Future Stellar Threat?

gl710_skyview

Gliese 710 inbound…(Credit: The Sloan Digital Sky Survey).

   Our quiet corner of the local galaxy may be in for a future interloper. A possible solar system side-swipe comes in the form of Gliese 710, an unassuming +10 magnitude orange dwarf star currently 63 light years distant in the constellation Serpens. As we swirl around the center of our galaxy, stellar neighbors come and go like in-laws during your favorite respective obligatory familial holiday season. The low proper motion of this star hid its true nature until about a decade ago; generally, the lower the apparent motion, the more distant the star. Gliese 710, however, fits into a different class; a star that shows a low apparent motion because it’s moving towards us. Closest approach has been calculated by astronomer Joan Garcia-Sanchez of JPL as about 1.3 light years in 1.5 million years time. Doesn’t sound like much? Well, this skirts the edge of our Oort Cloud, that vast reservoir of comets that extends out to about 1.6 light years distant…Gliese 710 stands an 86% chance of breaking this threshold. In addition, a 2007 review of Hipparcos data by Vadim V. Bobylev shows that this star may pass as close as 0.02 of a light year, about 50 times farther than the (sometimes) planet Pluto. This could make things really interesting, as Gliese 710 could really stir things up in our Oort cloud. And of course, there is the question of whether or not Gliese 710 has an Oort Cloud of its own. More than likely, this pulse of comets will last for about a several million year span of time. Could our inner solar system have sustained such shocks before? One only has to look at the crater-scarred surface of our Moon to realize the inner solar system has served as a shooting gallery over the eons. The statistical probability of a really (i.e. 1,000 AU) approach is about 1 in 10,000, so don’t max out those credit cards just yet… this uncertainly stems from incomplete knowledge of all the gravitational factors at work. As more sensitive astrometrical platforms, such as ESA’s Gaia spacecraft come online, the nature of the threat from Gliese 710 will be more precisely known. At its closest approach, this inbound star will be about as bright as the red giant star Antares… here’s to the neighbors!

11.04.10- Pale Blue Crescent.

 

(Credit: ESA/OSIRIS).

(Credit: ESA/OSIRIS).

 Earth as seen from Rosetta.

   It has been said innumerable times that in traveling into space, we’ve discovered the Earth. The Rosetta spacecraft reminded us what a unique place our home is on its trajectory altering flyby on November 13th of last year. Pictured above, you can easily tell that Earth is not a stagnant world, but a dynamic place, a place where interesting things are constantly happening. When the first astronomers looked at other planets in our solar system, it was thought that these worlds might not be any more hostile than, say, Antarctica. This concept still pervades some of the more campier of science fiction worlds, even today. But our explorations of the solar system have shown us something different, that even, say, a balmy day on Mars is magnitudes more hostile than Earth’s Gobi desert.

The European Space Agencies’ Rosetta spacecraft continues that spirit of exploration. Launched in 2004, it has performed a complex series of orbital slingshots that will cause it to eventually arrive at comet 67P/Churyumov-Gerasimenko in May 2014. There, it’ll take measurements of the icy interloper and even deposit a lander on the surface of a comet for the first time. Last year’s passage was Rosetta’s third and last flyby of its home world. The spacecraft had just passed asteroid 2867 Steins the year before, and is slated to perform a reconnaissance of asteroid 21 Lutetia in July of this year. The close passage with Earth gave it a 2.2 mile per second kick towards its final objective.

Do give pictures like those sent back by Rosetta pause, as we are the first and truly privileged generation to see our home world not as we’d like to see it, but as it actually is. Hey, we’re all on this Big Blue Marble together… perhaps we can get jaded by anything in time, but sights like these give us hope for our  survival as a species!

04.03.10: A Close Flyby of Phobos.

401-20080729-5851-6-na-1b-Phobos-Flyby_H1
Phobos on a pass of Mars Express last July. (Credit: ESA/DLR/FU Berlin/G. Neukum).

  

 The European Space Agencies’ (ESA) Mars Express orbiter completed the closest ever flyby of the misshapen Martian moon, Phobos, but don’t expect to see any mind blowing pictures…yet. Part of a series of 12 flybys, last nights’ pass skimmed to worldlet by 67 km, allowing its feeble gravity to deflect the space probe by a tiny but perceptible amount. This will allow engineers on the ground to get an idea of the internal density and composition of Phobos. But to do so, all instruments must be silent, so scientists can isolate minute oscillations on the probes carrier signal via the Doppler Effect. But take heart; Mars Express will further probe the moon on future passes via its MARIS radar, and will have its cameras switched on during next weeks’ March 7th pass…expect more cool pics soon!

26.10.09:Seeing Starspots.

A simulation of Corot-2a with transiting hot Jupiter and starspots. (Simulation and phot by author).

A simulation of Corot-2a with transiting hot Jupiter and starspots. (Simulation and photo by author).

We know more about our Sun than any other star because it gives us the opportunity to study solar activity up close. But just how normal is it? Recently, astronomers have been able to spy activity on other suns, teasing the data out of exoplanet transits. These are planets that happen to cross the tiny visible face of their parent star as seen from our line of sight and thus exhibit a tiny but measurable dip in their apparent brightness. Earlier this year, a team at the Hamburg Observatory has been refining this technique by monitoring the star Corot-2a. A younger Sun-like star, Corot-2a spins once every 4.5 earth days and possesses a transiting “hot Jupiter” which orbits once every 1.74 days. Examining a statistical analysis of the light curve as seen by the European Space Agencies’ (ESA) prolific Corot space observatory has yielded “notches” in the smooth curve, a tell-tale sign of “starspot” activity. This was conducted over 80 successive transits. The goal is to begin puzzling together a “butterfly diagram” for alien suns, much like the familiar 11 year cycle diagram yielded by Sporer’s Law for our own Sun. Doubtless, other suns follow different cycles, and this data will add to our understanding of stellar evolution. This will also answer such questions about our own Sun, such as; why do sunspots never form above a particular latitude? Are there larger interwoven cycles? And just what was our Sun like in its juvenile days?

23.9.9 CoRoT-7b: A Rare Earth.

Not a prime vacation spot! (Credit: Artist's Impression/ESA).

Not a prime vacation spot! (Credit: Artist's Impression/ESA).

The “Super-Earths” are getting smaller. Recently, the ESA announced that an exoplanet discovered on February 3rd of this year by the CoRoT (Convection Rotation and planetary Transit) satellite is one of the lightest yet… at about five Earth masses, this transiting exoplanet is about twice the diameter of the Earth. But don’t pack your bags just yet; CoRoT-7b as its designated, also zips around its host star every 20.4 hours at a distance 23 times closer than Mercury! This bakes the rocky world with temps in excess of 2000 degrees Celsius. The parent star itself is slighter cooler and younger than our Sun. Follow up measurements by HARPS, the ground based High Accuracy Radial velocity planet Searcher spectrograph at the La Silla Observatory in Chile helped tease out the radial speed and yielded an unexpected bonus; another Earth-like world, CoRoT-7c, which orbits at a relatively sedate 3 days and 17 hours and is 8 times the mass of the Earth. Such bizzare systems may become the norm in the coming years, as exoplanet detection technology becomes more sensitive. The CoRoT-7 system is located about 500 light years away in the plane of the Milky Way galaxy in the constellation Monoceros.

Titan Unveiled by Ralph Lorenz & Jacqueline Mitton

Cover.

A New Look: Three Faces of Titan.    

   Perhaps no world in the Solar System is as enigmatic as Titan. Until the last decade or so, what was known about this distant moon of Saturn could barely fill out a postcard, let alone a book. Titan Unveiled published by Princeton University Press is the first book solely dedicated to the moon, centering mostly on the phenomenally successful Cassini-Huygens mission to the ringed planet. [Read more...]