Posted on by Nancy Atkinson

The Moon Helps Radio Astronomers Search for Neutrinos

Radio astronomers get an assist from the Moon. Credit: Ted Jaeger, University of Iowa, NRAO/AUI/NSF

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From an NRAO press release:

Seeking to detect mysterious, ultra-high-energy neutrinos from distant regions of space, a team of astronomers used the Moon as part of an innovative telescope system for the search. Their work gave new insight on the possible origin of the elusive subatomic particles and points the way to opening a new view of the Universe in the future.

The team used special-purpose electronic equipment brought to the National Science Foundation’s Very Large Array (VLA) radio telescope, and took advantage of new, more-sensitive radio receivers installed as part of the Expanded VLA (EVLA) project. Prior to their observations, they tested their system by flying a small, specialized transmitter over the VLA in a helium balloon.

In 200 hours of observations, Ted Jaeger of the University of Iowa and the Naval Research Laboratory, and Robert Mutel and Kenneth Gayley of the University of Iowa did not detect any of the ultra-high-energy neutrinos they sought. This lack of detection placed a new limit on the amount of such particles arriving from space, and cast doubt on some theoretical models for how those neutrinos are produced.

Neutrinos are fast-moving subatomic particles with no electrical charge that readily pass unimpeded through ordinary matter. Though plentiful in the Universe, they are notoriously difficult to detect. Experiments to detect neutrinos from the Sun and supernova explosions have used large volumes of material such as water or chlorine to capture the rare interactions of the particles with ordinary matter.

The ultra-high-energy neutrinos the astronomers sought are postulated to be produced by the energetic, black-hole-powered cores of distant galaxies; massive stellar explosions; annihilation of dark matter; cosmic-ray particles interacting with photons of the Cosmic Microwave Background; tears in the fabric of space-time; and collisions of the ultra-high-energy neutrinos with lower-energy neutrinos left over from the Big Bang.

Radio telescopes can’t detect neutrinos, but the scientists pointed sets of VLA antennas around the edge of the Moon in hopes of seeing brief bursts of radio waves emitted when the neutrinos they sought passed through the Moon and interacted with lunar material. Such interactions, they calculated, should send the radio bursts toward Earth. This technique was first used in 1995 and has been used several times since then, with no detections recorded. The latest VLA observations have been the most sensitive yet done.

“Our observations have set a new upper limit — the lowest yet — for the amount of the type of neutrinos we sought,” Mutel said. “This limit eliminates some models that proposed bursts of these neutrinos coming from the halo of the Milky Way Galaxy,” he added. To test other models, the scientists said, will require observations with more sensitivity.

“Some of the techniques we developed for these observations can be adapted to the next generation of radio telescopes and assist in more-sensitive searches later,” Mutel said. “When we develop the ability to detect these particles, we will open a new window for observing the Universe and advancing our understanding of basic astrophysics,” he said.

The scientists reported their work in the December edition of the journal Astroparticle Physics.

Source: NRAO

Posted on by Nancy Atkinson

Enceladus Fissures Keep Getting Warmer and More Complex

Small water ice particles fly from fissures in the south polar region of Saturn's moon Enceladus in this image taken during the Aug. 13, 2010, flyby of the moon by NASA's Cassini spacecraft. Image credit: NASA/JPL/SSI

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As Cassini scientists await the data from today’s flyby of Enceladus, images and data from August of this year have provided more insight into the active fissures on the icy moon’s south polar region. These geyser-spewing fractures are warmer and more complicated than previously thought.

“The exquisite resolution obtained on one segment of the Damascus fracture — one of the most active regions within the south polar terrain — has revealed a surface temperature reaching a staggering 190 Kelvin, or 120 degrees below zero Fahrenheit,” said Cassini imaging team lead Carolyn Porco, in an email announcing the new images. “Far from the fractures, the temperature of the south polar terrain dips as low as 52 Kelvin, or 365 degrees below zero Fahrenheit.”

Porco said that what this means is that a phenomenal amount of heat is emerging from the fractures which are “undoubtedly the result of the tidal flexing of Enceladus brought about by its orbital resonance with Dione. However, details of this heating process are still unclear and are being studied at this very moment.”

This image shows a high-resolution heat intensity map of part of the south polar region of Saturn's moon Enceladus, made from data obtained by NASA's Cassini spacecraft. Image credit: NASA/JPL/GSFC/SWRI/SSI

The flyby on August 13, 2010 provided infrared spectroscopy along with high resolution images which have enabled scientists to construct the highest-resolution heat intensity maps yet of the hottest part of a region of long fissures spraying water vapor and icy particles from Enceladus. These fissures — known as “tiger stripes,” appear to be laid on in a complex web, and could be connected underground.

Additional high-resolution spectrometer maps of one end of the tiger stripes Alexandria Sulcus and Cairo Sulcus reveal never-before-seen warm fractures that branch off like split ends from the main tiger stripe trenches. They also show an intriguing warm spot isolated from other active surface fissures.

“The ends of the tiger stripes may be the places where the activity is just getting started, or is winding down, so the complex patterns of heat we see there may give us clues to the life cycle of tiger stripes,” said John Spencer, a Cassini team scientist based at Southwest Research Institute in Boulder, Colo.

The temperature measured in this flyby appears slightly higher than previously measured temperatures at Damascus, which were around 170 Kelvin (minus 150 degrees Fahrenheit).

Spencer said he isn’t sure if this tiger stripe is just more active than it was the last time Cassini’s spectrometer scanned it, in 2008, or if the hottest part of the tiger stripe is so narrow that previous scans averaged its temperature out over a larger area. In any case, the new scan had such good resolution, showing details as small as 800 meters (2,600 feet), that scientists could see for the first time warm material flanking the central trench of Damascus, cooling off quickly away from the trench. The Damascus thermal scan also shows large variations in heat output within a few kilometers along the length of the fracture. This unprecedented resolution will help scientists understand how the tiger stripes deliver heat to the surface of Enceladus.

Cassini acquired the thermal map of Damascus simultaneously with a visible-light image where the tiger stripe is lit by sunlight reflecting off Saturn. The visible-light and thermal data were merged to help scientists understand the relationships between physical heat processes and surface geology.

“Our high-resolution images show that this section of Damascus Sulcus is among the most structurally complex and tectonically dynamic of the tiger stripes,” said imaging science team associate Paul Helfenstein of Cornell University, Ithaca, N.Y. Some details in the appearance of the landforms, such as a peculiar pattern of curving striations along the flanks of Damascus, had not previously been noticed in ordinary sunlit images.

ets of water ice particles spew from Saturn's moon Enceladus in this image obtained by NASA's Cassini spacecraft on Aug. 13, 2010. Image credit: NASA/JPL/SSI

The Aug. 13 flyby of Enceladus is the last one dedicated to thermal mapping until 2015 and also gave Cassini its last look at any part of the active south polar region in sunlight.

The flyby today will aid in understanding the interior of the moon through gravity measurements.

To see more images from the August flyby, see Cassini website, and the CICLOPS imaging site.

Source: JPL, Porco email

Posted on by Nancy Atkinson

Science Sees Farther: Extraterrestrial Life

Are we alone in the universe? Can we save the lives of millions with new vaccines? How can we manage the increasing demands on our planet’s resources? Scientists try to answer these questions and more as part of a celebration of the 350th year of The Royal Society, the UK’s national academy of sciences. The Society has unveiled a new section on their website today, called “Science Sees Farther”, which includes essays, interviews and more on 12 different scientific topics, including extraterrestrial life, aging, health, climate change, and geoengineering, as well as discussions of the always-present uncertainties in science and how the internet has changed the science landscape.
Continue reading “Science Sees Farther: Extraterrestrial Life”

Posted on by Nicholos Wethington

Exoplanet Discovery Lists top 500

An artist's impression of a transiting exoplanet. Credit: ESA C Carreau

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It was only a little over a year ago that the 400th extrasolar planet was confirmed, but time flies when you’re discovering exoplanets. The 19th of November 2010 marked the date that over 500 exoplanets had been confirmed on The Extrasolar Planets Encyclopedia.

Though it’s an arbitrary number to celebrate, the fact that we’ve confirmed the existence over 500 exoplanets since their initial discovery 20 years ago is deserving of merriment. Discovery of exoplanets has really ramped up over the last few years, thanks in part to the ESA’s COROT satellite, the Hubble and Spitzer space telescopes, the Keck Interferometer, and the improvement of observational techniques to discover and confirm exoplanets. NASA’s Kepler spacecraft has over 700 candidates for exoplanets. Only 7 planets have been confirmed after being discovered by the Kepler spacecraft so far, though.

Jean Schneider, an astrobiologist at the Paris-Meudon Observatory, keeps up a database of the confirmed exoplanetary discoveries at The Extrasolar Planets Encyclopedia. He posted a warning about how muddle the declaration of “the discovery of the 500th exoplanet” could be. He wrote in the warning:

“The number of exoplanets, recored for instance at http://exoplanet.eu is necessarily subject to some uncertainty for several reasons:
– the mass limit below which a substellar object is called a planet
is somewhat arbitrary
– the mass measurement is always affected by some instrumental inaccuracy
– whatever this mass limit is, the true mass for most planets is subject
to some uncertainty, intrinsic to the detection method (unkown
inclination of the orbit, modelisation of planet atmosphere)
– some planet detections, even published in refereed papers, are sometimes
retracted afterwards

For all these reasons
1/ The boundary between “confirmed”/”unconfirmed” planets is somewhat fuzzy
2/ The number of planet candidates at http://exoplanet.eu ;(collected
in the survey of professional litterature, conferences or websites)
is affected by an uncertainty of a few units.”

In essence, to say that there is a “500th exoplanet” is really not possible, given that there needs to be confirmation of the planet. Even after that confirmation, there could be the possible retraction of the planet from the database. 5 confirmations were posted on the 19th, all of them published in refereed papers and discovered in 2010. This kicked the total over 500. But then another was announced the next day, and it was discovered in 2007 but only recently confirmed. So, putting a number on the 500th extrasolar planet to be confirmed is pretty much impossible, arbitrary at best.

Schneider was interviewed by Scientific American on just why he is the keeper of the encyclopedia, and some of his thoughts on the discoveries made so far and the future of the field. The text of the interview is available here.

Complicating matters even further, there is another running tally of extrasolar planets maintained by the NASA’s Jet Propulsion Laboratory at PlanetQuest. Their count on the 22nd of November was only 497, and today rests at 500. The Extrasolar Planets Encyclopedia now stands at 504.

PlanetQuest has this video that succinctly describes the history of extrasolar planet discovery, for those interested:

Even if it’s arbitrary, you can still have that “500th exoplanet” party if you’d like, complete with Kepler satellite-shaped hats. Nobody will likely stop you; if they do, there will likely be another few dozen planets discovered – or a few retracted – by then anyways, making their point rather moot.

Source: MSNBC, PlanetQuest and The Extrasolar Planets Encyclopedia

Posted on by Nicholos Wethington

Christie’s to Auction off 1st Edition Works by Newton, Galileo

Cardinal Bellarmine had written in 1615 that the Copernican system could not be defended without "a true physical demonstration that the sun does not circle the earth but the earth circles the sun". Galileo considered his theory of the tides to provide the required physical proof of the motion of the earth. This theory was so important to him that he originally intended to entitle his Dialogue on the Two Chief World Systems the Dialogue on the Ebb and Flow of the Sea. For Galileo, the tides were caused by the sloshing back and forth of water in the seas as a point on the Earth's surface sped up and slowed down because of the Earth's rotation on its axis and revolution around the Sun. He circulated his first account of the tides in 1616, addressed to Cardinal Orsini. His theory gave the first insight into the importance of the shapes of ocean basins in the size and timing of tides; he correctly accounted, for instance, for the negligible tides halfway along the Adriatic Sea compared to those at the ends. As a general account of the cause of tides, however, his theory was a failure. If this theory were correct, there would be only one high tide per day. Galileo and his contemporaries were aware of this inadequacy because there are two daily high tides at Venice instead of one, about twelve hours apart. Galileo dismissed this anomaly as the result of several secondary causes including the shape of the sea, its depth, and other factors. Against the assertion that Galileo was deceptive in making these arguments, Albert Einstein expressed the opinion that Galileo developed his "fascinating arguments" and accepted them uncritically out of a desire for physical proof of the motion of the Earth. Galileo dismissed the idea, held by his contemporary Johannes Kepler, that the moon caused the tides. He also refused to accept Kepler's elliptical orbits of the planets, considering the circle the "perfect" shape for planetary orbits.Cardinal Bellarmine had written in 1615 that the Copernican system could not be defended without "a true physical demonstration that the sun does not circle the earth but the earth circles the sun". Galileo considered his theory of the tides to provide the required physical proof of the motion of the earth. This theory was so important to him that he originally intended to entitle his Dialogue on the Two Chief World Systems the Dialogue on the Ebb and Flow of the Sea. For Galileo, the tides were caused by the sloshing back and forth of water in the seas as a point on the Earth's surface sped up and slowed down because of the Earth's rotation on its axis and revolution around the Sun. He circulated his first account of the tides in 1616, addressed to Cardinal Orsini. His theory gave the first insight into the importance of the shapes of ocean basins in the size and timing of tides; he correctly accounted, for instance, for the negligible tides halfway along the Adriatic Sea compared to those at the ends. As a general account of the cause of tides, however, his theory was a failure. If this theory were correct, there would be only one high tide per day. Galileo and his contemporaries were aware of this inadequacy because there are two daily high tides at Venice instead of one, about twelve hours apart. Galileo dismissed this anomaly as the result of several secondary causes including the shape of the sea, its depth, and other factors. Against the assertion that Galileo was deceptive in making these arguments, Albert Einstein expressed the opinion that Galileo developed his "fascinating arguments" and accepted them uncritically out of a desire for physical proof of the motion of the Earth. Galileo dismissed the idea, held by his contemporary Johannes Kepler, that the moon caused the tides. He also refused to accept Kepler's elliptical orbits of the planets, considering the circle the "perfect" shape for planetary orbits.

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It’s too bad that they missed Black Friday, but you’ll at least be able to get a few gifts for that astronomy enthusiast friend of yours for Christmas (or even for yourself!). The auction house Christie’s will be putting on the block 160 pieces from Edward Tufte’s rare book collection December 2nd in New York City.

Among the works are original 1st edition copies of such books as Isaac Newton’s Opticks (1704), and Galileo Galilee’s Sidereus nuncius (1610) which is better known in English as The Starry Messenger. Galileo famously reported some of his early telescopic observations in this book, discovering the moons of Jupiter and craters and mountains on the Moon. There will also be a copy of René Descartes’ Principia philosophiae (1644) and various works by other famous astronomers, philosophers and scientists.

Edward Tufte is a Professor Emeritus of Political Science, Statistics, and Computer Science at Yale University. According to his bio on their site, “His research concerns statistical evidence and scientific visualization.” Looking through the Christie’s catalog, his interests in science history and visualization are well-represented, and the collection is quite impressive.

Of course, all of these items come at a price, rare and famous as they are. Would you expect anything less from such a notable auction house? Opticks is billed to sell for $30,000 – $40,000, Principia philosophiae for $6,000 – $8,000 and Siderius nuncius – the most expensive of the entire lot – is valued at between $600,000-$800,000 (all amounts in US Dollars). Here are a few other items for sale, accompanied by their expected fetching price:

– John Snow – On the Mode of Communication of Cholera (1849) $10,000 – $15,000 This is an important book that revolutionized our understanding of disease transmission. Steven Johnson’s book Ghost Map is based on this work, and is a fascinating read.

– Euclid – Elements $400 – $600 A 1589 copy of this important mathematical work that underlies our understanding of physics and math today. Euclid was born around 300 BC, and the oldest fragment of the Elements only dates to 100 AD.

– Thomas Hobbes – Leviathan, or The Matter, Forme, & Power of a Common-Wealth(1651). $15,000 – $20,000 A very influential work in the history of political philosophy and social contract theory. You may recognize this quote from chapter 12 of the book, “…and the life of man, solitary, poor, nasty, brutish and short.”

– Christiaan Huygens – Systema Saturnium (1659) $25,000 – $35,000 This is a digest of Huygens’ observations of the Saturnian system, and contains one of the first drawings of the Orion nebula.

– Edmund Halley – A description of the passage of the shadow of the moon, over England, in the total eclipse of the sun, on the 22nd day of April 1715 in the morning. (1715) $15,000 – $20,000 An illustrated broadside of Halley’s prediction of the shadow cast by the lunar eclipse on April 22nd, 1715. There are a few other works from Halley for sale as well.

I suggest sifting through the catalog – there are a lot of detailed photos and descriptions of the books for sale, many of them rare gems from the history of philosophy and astronomy and science.

Tufte is also selling a piece of his own artwork for $50,000 – $70,000 titled, Pioneer Space Plaque: A Cosmic Prank (2010). A digital print that uses animation electronics, it is a redesign – and parody – of the original plaques that still fly aboard the Pioneer 10 and 11 probes. For a picture, visit the auction page.

Source: Scientific American, Christie’s

Posted on by Nicholos Wethington

An Apertif to the Next Radio Astronomy Entrée

A new detector at the Westerbork Synthesis Radio Telescope (WSRT) allows for a much wider view of the sky in the radio spectrum. In this image, the two pulsars are separated by over 3.5 degrees of arc in the sky. Image Credit: ASTRON

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To aid in the digestion of a new era in radio astronomy, a new technique for improving the is unfolding at the Westerbork Synthesis Radio Telescope (WSRT) in the Netherlands. By adding a plate of detectors to the focal plane of just one of the 14 radio antennas at the WSRT, astronomers at the Netherlands Institute for Radio Astronomy (ASTRON) have been able to image two pulsars separated by over 3.5 degrees of arc, which is about 7 times the size of the full Moon as seen from Earth.

The new project – called Apertif – uses an array of detectors in the focal plane of the radio telescope. This ‘phased array feed’ – made of 121 separate detectors – increases the field of view of the radio telescope by over 30 times. In doing so, astronomers are able to see a larger portion of the sky in the radio spectrum. Why is this important? Well, in keeping with our food course analogy, imagine trying to eat a bowl of soup with a thimble – you can only get a small portion of the soup into your mouth at a time. Then imagine trying to eat it with a ladle.

This same analogy of surveying and observing the sky for radio sources holds true. Dr. Tom Oosterloo, the Principle Investigator of the Apertif project, explains the meat of the new technique:

“The phased array feed consists of 121 small antennas, closely packed together. This matrix covers about 1 square meter. Each WSRT will have such a antenna matrix in its focus. This matrix fully samples the radiation field in the focal plane. By combining the signals of all 121 elements, a ‘compound beams'[sic] can be formed which can be steered to be pointing at any location inside a region of 3×3 degrees on the sky. By combining the signals of all 121 elements, the response of the telescope can be optimised, i.e. all optical distortions can be removed (because the radiation field is fully measured). This process is done in parallel 37 times, i.e. 37 compound beams are formed. Each compound beam basically functions as a separate telescope. If we do this in all WSRT dishes, we have 37 WSRTs in parallel. By steering all the beams to different locations within the 3×3 degree region, we can observe this region entirely.”

In other words, traditional radio telescopes use only a single detector in the focal plane of the telescope (where all of the radiation is focused by the telescope). The new detectors are somewhat like the CCD chip in your camera, or those in use in modern optical telescopes like Hubble. Each separate detector in the array receives data, and by combining the data into a composite image a high-quality image can be captured.

The new array will also widen the field of view of the radio telescope, which allowed for this most recent observation of widely separated pulsars in the sky, a milestone test for the project. As an added bonus, the new detector will increase the efficiency of the “aperture” to around 75%, up from 55% with the traditional antennas.

Dr. Oosterloo explained, “The aperture efficiency is higher because we have much more control over the radiation field in the focal plane. With the classic single antenna systems (as in the old WSRT or as in the eVLA), one measures the radiation field in a single point only. By measuring the radiation field over the entire focal plane, and by cleverly combining the signals of all elements, optical distortion effects can be minimised and a larger fraction of the incoming radiation can be used to image the sky.”

This image illustrates the larger field of view afforded by the new instrument. Image Credit: ASTRON

For now, there is only one of the 14 radio antennas equipped with Apertif. Dr. Joeri Van Leeuwen, a researcher at ASTRON, said in an email interview that in 2011, 12 of the antennas will be outfitted with the new detector array.

Sky surveys have been a boon for astronomers in recent years. By taking enormous amounts of data and making it available to the scientific community, astronomers have been able to make many more discoveries than they would have been able to by applying for time on disparate instruments.

Though there are some sky surveys in the radio spectrum that have been completed so far – the VLA FIRST Survey being the most prominent – the field has a long way to go. Apertif is the first step in the direction of surveying the whole sky in the radio spectrum with great detail, and many discoveries are expected to be made by using the new technique.

Apertif is expected to discover over 1,000 pulsars, based on current modeling of the Galactic pulsar population. It will also be a useful tool in studying neutral hydrogen in the Universe on large scales.

Dr. Oosterloo et. al. wrote in a paper published on Arxiv in July, 2010, “One of the main scientific applications of wide-field radio telescopes operating at GHz frequencies is to observe large volumes of space in order to make an inventory of the neutral hydrogen in the Universe. With such information, the properties of the neutral hydrogen in galaxies as function of mass, type and environment can be studied in great detail, and, importantly, for the first time the evolution of these properties with redshift can be addressed.”

Adding the radio spectrum to the visible and infrared sky surveys would help to fine-tune current theories about the Universe, as well as make new discoveries. The more eyes on the sky we have in different spectra, the better.

Though Apertif is the first such detector in use, there are plans to update other radio telescopes with the technology. Dr. Oosterloo said of other such projects, “Phased array feeds are also being built by ASKAP, the Australia SKA Pathfinder. This is an instrument of similar characteristics as Apertif. It is our main competitor, although we also collaborate on many things. I am also aware of a prototype being tested at Arecibo currently. In Canada, DRAO [Dominion Radio Astrophysical Observatory] is doing work on phased array feed development. However, only Apertif and ASKAP will construct an actual radio telescope with working phased array feeds in the short term.”

On November 22nd and 23rd, a science coordination meeting was held about the Apertif project in Dwingeloo, Drenthe, Netherlands. Dr. Oosterloo said that the meeting was attended by 40 astronomers, from Europe, the US, Australia and South Africa to discuss the future of the project, and that there has been much interest in the potential of the technique.

Sources: ASTRON press release, Arxiv, email interview with Dr. Tom Oosterloo and Dr. Joeri Van Leeuwen

Posted on by Nancy Atkinson

Russia Wants to Build “Sweeper” to Clean up Space Debris

Trackable objects in Low Earth Orbit. Image Credit: ESA

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Russia is looking to build a $2 billion orbital “pod” that would sweep up satellite debris from space around the Earth. According to a post on the Russian Federal Space Agency, Roscosmos’ Facebook site, (which seems to confirm an earlier article by the Interfax news agency) the cleaning satellite would work on nuclear power and be operational for about 15 years. The Russian rocket company, Energia proposes that they would complete the cleaning satellite assembly by 2020 and test the device no later than in 2023.

“The corporation promises to clean up the space in 10 years by collecting about 600 defunct satellites on the same geosynchronous orbit and sinking them into the oceans subsequently,” Victor Sinyavsky from the company was quoted as saying.

Sinyavsky said Energia was also in the process of designing a space interceptor that would to destroy dangerous space objects heading towards the Earth.

No word on exactly how the space debris cleaner would work, of how it would push dead satellites and other debris into a decaying orbit so that objects would burn up in the atmosphere, or if it might somehow gather up or “vacuum” debris. But at least someone is thinking about space debris and asteroid deflection and putting more than just a few rubles (60 billion of ’em) towards these concepts.

Sources: Xinhuanet, Facebook

Posted on by Nancy Atkinson

Astronomy Cast Ep. 208: The Spitzer Space Telescope

The Spitzer Space Telescope. Credit: NASA

Last week we talked about Lyman Spitzer, and this week we’ll take a look at the orbiting observatory that bears his name: the Spitzer Space Telescope. Designed to see into the infrared spectrum, Spitzer has returned images of objects that were previously hidden to astronomers by thick shrouds of gas and dust.

Click here to download the episode

Spitzer Space Telescope – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

Posted on by Nancy Atkinson

Clash of the Titan Galaxies

NGC 520 — also known as Arp 157 -- is actually a mashup of two gigantic galaxies. Credit: ESO

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Is this galaxy exploding? Although that’s what it might look like, this is actually two gigantic galaxies crashing into each other. NGC 520 — also known as Arp 157 — is a mashup of two huge galaxies, now combining into one. We can’t really watch the process, as it happens extremely slowly — over millions of years, and the whole process started about 300 million years ago. Apr 157 is about 100,000 light-years across and is now in the middle stage of the merging process, as the two nuclei haven’t come together yet, but the two discs have. The merger features a tail of stars and a prominent dust lane. NGC 520 is one of the brightest interacting galaxies in the sky and lies in the direction of Pisces (the Fish), approximately 100 million light-years from Earth.

This image was taken by the ESO Faint Object Spectrograph and Camera attached to the 3.6-metre telescope at La Silla in Chile.

You’d need about a 4-inch telescope to see this 12th magnitude object yourself. Here’s the location: RA: 1h 24m 35.1s, Declination: +03° 47? 33?. Or put in those coordinates in Google Sky to see it there.

Source: ESO