Ready for the next big ‘Comet of the Century?’ Yeah, us too. Cometary apparitions are the big unknown in backyard astronomy, an eternal uncertainty in the clockwork goings-on of the universe. Continue reading “Comet Craziness: 252P LINEAR Brightens, and a Close Pass for BA14 PanSTARRS”
With the ever-increasing affordability of technology, Virtual Reality is making its way into people’s homes. Systems like the Oculus Rift, and Sony’s PlayStation VR when it’s released next Fall, are becoming increasingly common. These systems, and others to come, will allow people to not only watch VR movies and play VR games, but also to explore space from the comfort of their own homes. This won’t be the only intersection of Virtual Reality and space, though.
NASA, as is often the case, has already blazed a trail when it comes to VR and space. They’ve been using VR to train astronauts for quite a while now. They have a whole lab dedicated to it, called the Virtual Reality Lab, located at the Johnson Space Center in Houston, Texas. At this facility, astronauts use VR to prepare them for working aboard the ISS.
NASA has flirted with other VR solutions as well. They used an Oculus Rift and a VR Treadmill combined with Mars footage from the Curiosity rover to create a virtual walk on the surface of Mars.
NASA’s use of VR is the most advanced around, naturally, but it’s not something most of us will ever encounter. For the rest of us, VR is making it’s way into our space-loving lives in other ways.
A company called Immersive Education has created a VR simulation of the Apollo 11 mission. It allows users to re-live the mission. You can look around the inside of the spacecraft, look out the window toward Earth, even watch and listen as astronauts walk on the surface of the Moon. The company promises “Historically accurate spacecraft interiors and exteriors.”
Here, Apollo astronaut Charlie Duke checks out the Apollo 11 VR on Oculus Rift.
Companies DEEP Inc. and Freedom 360 collaborated with the Canadian Space Agency to create a VR film called “The Edge of Space.” They used 360 degree cameras to record the view from a balloon that reached an altitude of 40km above Earth. Check out their video here. To get the real interactive effect, visit their page to download their app and view it.
Then there’s what I call virtual VR. Or you could call it “headsetless” VR, I guess. Though it lacks the immersion of full VR, it’s still cool. It’s a virtual planetarium from Escapist Games Limited, called Star Chart. Star Chart allows users to cruise through the Solar System and the Universe, checking out stars, nebulae, planets and other objects along the way.
This is just the beginning of VR’s entertainment and educational capabilities. With the growing affordability of VR, and the technological advancements to come, there’s going to some great implementations of VR technology for we space enthusiasts. I expect that in the next few years, we wannabe space explorers will be able to explore the surface of other worlds with VR, right in our own living rooms.
All right, maybe not blinking like a flashlight (or a beacon on the tippity-top of a communication tower—don’t even start that speculation up) but the now-famous “bright spots” on the dwarf planet Ceres have been observed to detectably increase and decrease in brightness, if ever-so-slightly.
And what’s particularly interesting is that these observations were made not by NASA’s Dawn spacecraft, currently in orbit around Ceres, but from a telescope right here on Earth.
Researchers using the High Accuracy Radial velocity Planet Searcher (HARPS) instrument on ESO’s 3.6-meter telescope at La Silla detected “unexpected” changes in the brightness of Ceres during observations in July and August of 2015. Variations in line with Ceres’ 9-hour rotational period—specifically a Doppler effect in spectral wavelength created by the motion of the bright spots toward or away from Earth—were expected, but other fluctuations in brightness were also detected.
“The result was a surprise,” said Antonino Lanza from the INAF–Catania Astrophysical Observatory, co-author of the study. “We did find the expected changes to the spectrum from the rotation of Ceres, but with considerable other variations from night to night.”
Watch a video below illustrating the rotation of Ceres and how reflected light from the bright spots within Occator crater are alternately blue- and red-shifted according to the motion relative to Earth.
First observed with Hubble in December 2003, Ceres’ curious bright spots were resolved by Dawn’s cameras to be a cluster of separate regions clustered inside the 60-mile (90-km) -wide Occator crater. Based on Dawn data they are composed of some type of highly-reflective materials like salt and ice, although the exact composition or method of formation isn’t yet known.
Since they are made of such volatile materials though, interaction with solar radiation is likely the cause of the observed daily brightening. As the deposits heat up during the course of the 4.5-hour Ceres daytime they may create hazes and plumes of reflective particles.
“It has been noted that the spots appear bright at dawn on Ceres while they seem to fade by dusk,” noted study lead author Paolo Molaro in the team’s paper. “That could mean that sunlight plays an important role, for instance by heating up ice just beneath the surface and causing it to blast off some kind of plume or other feature.”
Once day turns to night these hazes will re-freeze, depositing the particles back down to the surface—although never in exactly the same way. These slight differences in evaporation and condensation could explain the random variation in daily brightening observed with HARPS.
These findings have been published the journal Monthly Notices of the Royal Astronomical Society (full text on arXiv here.)
Last week we talked about stars feasting on other stars. This week, we scale the whole process up a notch, with galaxies feasting on other galaxies. Come for the carnage, stay for the science.
Continue reading “Astronomy Cast Ep. 407: Galactic Cannibalism”
What is a treasure? A pirate’s hoard of gold coins safely locked up in a chest would certainly fit. But would you say that something is a treasure when it’s freely available to anyone who wants to take the time? Seems unlikely, doesn’t it. Yet you may change your mind once you take in André van der Hoeven’s book “Treasures of the Universe – Amateur and Professional Visions of the Cosmos”. Within it are striking images that display the natural wealth and beauty that constantly surrounds us and that no chest could ever lock up.
Astrophotography at its core is quite simple; at night, take a camera outside, point the lens up and snap the shutter release. Anyone can do it. However, putting reason to what one captures in the lens is quite a different story. And to add further complexity, consider combining your captured image with someone else’s who’s taken a picture while on another continent or while in space. Last, after taking thousands of images, identify those with artistic as well as scientific merit.
Yes, this is a more complete way of considering astrophotography. And many people are partaking in it. So here’s a book that’s selling its version of night sky images. For anyone who enjoys the night skies, there’s a lot to like. The contents are divided into four groups; galaxies, clusters, nebulae and our solar system. Most images from beyond our solar system are well known, whether of entries in the Messier catalogue or the New General Catalogue (NGC). A few are of farther afield, such as from the Hubble eXtreme Deep Field.
The image presentation is often on a double page spread and has complementary text adjoining. The text provides the scientific merit usually by identifying how the subject of the image fits into the scheme of things, such as the supernova SN2011fe in the Galactic Wheel. The text also provides the photographic particulars, such as that of the Andromeda galaxy that resulted from the compilation of 11 000 separate snapshots. The selection of images makes for a fairly well known set and won’t lead to surprises. Given this, van der Hoeven’s book is a comfortable, complete treatise of his astrophotography.
Now views of space are everywhere on the Internet and other publications so you’re probably wondering “What’s this book bring to the table?” so to speak. After all, a lot of its images come from other government sources like the Hubble space telescope. That’s data free for anyone to peruse. And, the subject of the images, the universe, remains in place for anyone else to capture if they so desire. Both of these are true, but what isn’t obvious is the time and effort to create the images as well as the talent to engender a sense of artistry. Can you imagine the time to compile 11,000 pictures into one? Or spending over 27 night-time hours to collect data for one image? That’s the sort of time and effort involved.
Measuring artistry is another skill altogether and one of which I lay no great claim. Yet, looking at the composition of the spread of the Wizard Nebula warmly shrouded by a complex hydrogen cloud makes me pause. Yes, I know I’m looking at the result of the random arrangement of matter and energy. But there’s something just so darn compelling about the shapes and textures that makes me wonder. And I realize my wonder comes from the skill of the author in composing the shape. I’m impressed. This doesn’t mean that the author has claimed any predominance. Rather, throughout the book he provides encouragement and incitements for bigger and better. Whether it calls for astrophotography from the next-generation telescopes or for beginner astrophotographers to develop their skill, it pushes for more and better imagery. Yes, this book is more than just pretty pictures. It’s also instructive and telling. Another unusual aspect is that the book was funded through a Kickstarter.
As with a few other marvelous books with vistas of the universe, this book’s pages are in in a wide format (almost landscape size). The pages have matte-black background with clear white font text. The text for each image is usually clear, except for some with underlying images of light colours. These are few. For the selection of images, I find ones of galaxies and nebulae most rewarding. Finding shapes and patterns from clusters is more challenging.
And, after seeing the depth and expanse of the universe, I find the images from our solar system almost ordinary, though I know I shouldn’t. I like the section at the book’s end that describes the image details including the telescope, the camera and the exposures for various filters. Perhaps I can use these to dabble at my own artistry. I also appreciate the credits that list all the data sources and perhaps the people who processed the data, though these aren’t always obvious. I don’t like that the book had to eventually come to an end. I could have kept looking at many more pages.
Treasures are a measure of worth. For those who like gold, a pirate’s chest may be the ultimate high. For those who are drawn to the night, to the limitlessness of space, then the jewels of the night sky are the only ones worth viewing. For you who like the night, let André van der Hoeven’s book “Treasures of the Universe – Amateur and Professional Visions of the Cosmos” spirit you away to a viewing pleasure. With it in your hands you will hold more than any pirate’s chest could ever contain.
The cooperative Euro-Russian ExoMars 2016 expedition is now en route to the Red Planet after successfully firing its upper stage booster one final time on Monday evening, March 15, to blast free of the Earth’s gravitational tug and begin a 500 million kilometer interplanetary journey in a bold search of indications of life emanating from potential Martian microbes.
The vehicle is in “good health” with the solar panels unfurled, generating power and on course for the 500 Million kilometer (300 million mile) journey to Mars.
“Acquisition of signal confirmed. We have a mission to Mars!” announced Mission Control from the European Space Agency.
The joint European/Russian ExoMars spacecraft successfully blasted off from the Baikonur Cosmodrome in Kazakhstan atop a Russian Proton-M rocket at 5:31:42 a.m. EDT (0931:42 GMT), Monday, March 14, with the goal of searching for possible signatures of life in the form of trace amounts of atmospheric methane on the Red Planet.
Video caption: Blastoff of Russian Proton rocket from the Baikonur Cosmodrome carrying ExoMars 2016 mission on March 14, 2016. Credit: Roscosmos
The first three stages of the 191-foot-tall (58-meter) Russian-built rocket fired as scheduled over the first ten minutes and lofted the 9,550-pound (4,332-kilogram) ExoMars to orbit.
Three more firings from the Breeze-M fourth stage quickly raised the probe into progressively higher temporary parking orbits around Earth.
But the science and engineering teams from the European Space Agency (ESA) and Roscosmos had to keep their fingers crossed and endure an agonizingly long wait of more than 10 hours before the fourth and final ignition of the Proton’s Breeze-M upper stage required to break the bonds of Earth.
The do or die last Breeze-M upper stage burn with ExoMars still attached was finally fired exactly as planned.
The probe was released at last from the Breeze at 20:13 GMT.
However, it took another long hour to corroborate the missions true success until the first acquisition of signal (AOS) from the spacecraft was received at ESA’s control centre in Darmstadt, Germany via the Malindi ground tracking station in Africa at 5:21:29 p.m. EST (21:29 GMT), confirming a fully successful launch with the spacecraft in good health.
It was propelled outwards to begin a seven-month-long journey to the Red Planet to the great relief of everyone involved from ESA, Roscosmos and other nations participating. An upper stage failure caused the total loss of Russia’s prior mission to Mars; Phobos-Grunt.
“Only the process of collaboration produces the best technical solutions for great research results. Roscosmos and ESA are confident of the mission’s success,” said Igor Komarov, General Director of the Roscosmos State Space Corporation, in a statement.
The ExoMars 2016 mission is comprised of a joined pair of European-built spacecraft consisting of the Trace Gas Orbiter (TGO) plus the Schiaparelli entry, descent and landing demonstrator module, built and funded by ESA.
“It’s been a long journey getting the first ExoMars mission to the launch pad, but thanks to the hard work and dedication of our international teams, a new era of Mars exploration is now within our reach,” says Johann-Dietrich Woerner, ESA’s Director General.
“I am grateful to our Russian partner, who have given this mission the best possible start today. Now we will explore Mars together.”
The cooperative mission includes significant participation from the Russian space agency Roscosmos who provided the Proton-M launcher, part of the science instrument package, the surface platform and ground station support.
The Trace Gas Orbiter (TGO) and Schiaparelli lander are speeding towards Mars joined together, on a collision course for the Red Planet. They will separate on October 16, 2016 at distance of 900,000 km from the planet, three days before arriving on October 19, 2016.
TGO will fire thrusters to alter course and enter an initial four-day elliptical orbit around the fourth planet from the sun ranging from 300 km at its perigee to 96 000 km at its apogee, or furthest point.
Over the next year, engineers will command TGO to fire thrusters and conduct a complex series of ‘aerobraking’ manoeuvres that will gradually lower the spacecraft to circular 400 km (250 mi) orbit above the surface.
The science mission to analyse for rare gases, including methane, in the thin Martian atmosphere at the nominal orbit is expected to begin in December 2017.
As TGO enters orbit, the Schiaparelli lander will smash into the atmosphere and begin a harrowing six minute descent to the surface.
The main purpose of Schiaparelli is to demonstrate key entry, descent, and landing technologies for the follow on 2nd ExoMars mission in 2018 that will land the first European rover on the Red Planet.
The battery powered lander is expected to operate for perhaps four and up to eight days until the battery is depleted.
It will conduct a number of environmental science studies such as “obtaining the first measurements of electric fields on the surface of Mars that, combined with measurements of the concentration of atmospheric dust, will provide new insights into the role of electric forces on dust lifting – the trigger for dust storms,” according to ESA.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
The invention of the rocket changed space science forever. The Universe could only be inspected from the surface of the Earth, with all that atmosphere in the way, until rockets were invented. And as far as the modern age of rocketry goes, it all started 90 years ago with Robert Goddard’s liquid-fuelled rocket.
Goddard was a dreamer. He envisioned rocket-powered spacecraft plying the solar system. Obviously, he passed away before interplanetary travel materialized, but his work on rocketry certainly laid the groundwork for that eventual achievement. The Goddard Space Flight Center is named after him, and it’s doubtful that any engineering or technology student in the world doesn’t know who he is.
Goddard’s first liquid-fuelled rocket was modest by today’s standards, of course. But he had to solve several technical challenges to achieve it, and his ability to solve these challenges led to not only this first flight, but to a total of 34 rocket flights in 15 years, from 1926 to 1941. His rockets reached the altitude of 2.6 km (1.6 miles) and speeds of 885 km/h (550 mph.) He also patented 214 inventions.
Goddard is considered the father of modern rocket science, but he is actually one of three men who are considered the main contributors to modern rocketry. Russian Konstantin Tsiolkovsky (1858-1935) and German Hermann Oberth (1894-1989) are the other founding fathers of modern rocketry.
Goddard didn’t invent rocketry, of course. The Chinese used rockets as far back as the 13th century, and rockets made appearances throughout history as weapons and fireworks. But Goddard’s success at liquid-fuelled rocketry, and the capabilities that came with it, is when rocketry really got off the ground. (Sorry.)
Nowadays, Goddard is understood to be a driven and highly-intelligent person, the type of person who is responsible for advancing science and technology. But back in his time, before he had successful flights, he and his ideas were ridiculed. Check out this criticism from the New York Times, January 13th, 1920:
“That Professor Goddard, with his ‘chair’ in Clark College and the countenancing of the Smithsonian Institution, does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react — to say that would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools.”
Stinging words, to be sure, but people who know anything about the history of science are familiar with this kind of condemnation of brilliant people, coming from those who lack vision.
Now of course, we have huge rockets. Great thundering beasts that lift enormous loads out of Earth’s gravity well. And we’re so accustomed to rocket launches now that they barely make news. But I always get a kick out of imagining what people like Goddard would feel if they were able to view a launch of one of today’s behemoths, like the Ariane 5. I’m sure his chest would swelled with pride, and he would be amazed at what people have accomplished.
But his vindication wouldn’t just come from the huge leaps we’ve made in rocket technology, and the huge rockets we now routinely launch. It would also come from this retraction, delivered decades too late but with class, by the New York Times, on July 17 1969, the day after Apollo 11 launched:
Further investigation and experimentation have confirmed the findings of Isaac Newton in the 17th Century and it is now definitely established that a rocket can function in a vacuum as well as in an atmosphere. The Times regrets the error.
Images from the New Horizons spacecraft show a bite-mark shaped feature on the surface of Pluto. Scientists think that the feature is caused by the sublimation of methane ice, causing cliffs to erode and leaving a flat plain in their place. The images were captured just prior to New Horizon’s closest approach to Pluto on July 14th, 2015.
In the image above, which is of Pluto’s western hemisphere, three main features are shown. The first is Vega Terra, which as a raised plateau area. The second is the Piri Planitia, which is a flatter and lower area of plains. Piri Planitia shows an absence of craters, meaning it is geologically younger. Dividing Terra and Planitia are the Piri Rupes, the cliffs which have the bite-mark shaped feature that caught the interest of scientist.
The colored image on the right shows methane-rich areas in purple. Scientists think that as the methane ice of Piri Rupes is sublimated away into the atmosphere, the cliffs are removed and the flat plains of Piri Planitia take their place. The image also shows some methane mesas which have not sublimated away yet.
New Horizons’ data also shows that Piri Planitia has a higher content of water ice, which is shown in blue. Because of the frigid temperature on Pluto, it’s thought that this water ice is like bedrock. It is immobile, and as the methane ice is sublimated away, the water ice bedrock of Piri Planitia is left exposed.
Prior to New Horizons’ arrival at Pluto, it was generally thought that not much was happening at Pluto. But as these images show, and as New Horizons keeps proving, Pluto is far from an inactive place, and there’s a lot to hold the interest of planetary scientists.
Dark Matter is rightly called one of the greatest mysteries in the Universe. In fact, so mysterious is it, that we here in the opulent sky-scraper offices of Universe Today often joke that it should be called “Dark Mystery.” But that sounds like a cheesy History Channel show, and here at Universe Today we don’t like cheesy, so Dark Matter it remains.
Though we still don’t know what exactly Dark Matter is, we keep learning more about how it interacts with the rest of the Universe, and nibbling around at the edges of what it might be. But before we get into the latest news about Dark Matter, it’s worth stepping back a bit to remind ourselves of what is known about Dark Matter.
Evidence from cosmology shows that about 25% of the mass of the Universe is Dark Matter, also known as non-baryonic matter. Baryonic matter is ‘normal’ matter, which we are all familiar with. It’s made up of protons and neutrons, and it’s the matter that we interact with every day.
Cosmologists can’t see the 25% of matter that is Dark Matter, because it doesn’t interact with light. But they can see the effect it has on the large scale structure of the Universe, on the cosmic microwave background, and in the phenomenon of gravitational lensing. So they know it’s there.
Large galaxies like our own Milky Way are surrounded by what is called a halo of Dark Matter. These huge haloes are in turn surrounded by smaller sub-haloes of Dark Matter. These sub-haloes have enough gravitational force to form dwarf galaxies, like the Milky Way’s own Sagittarius and Canis Major dwarf galaxies. Then, these dwarf galaxies themselves have their own Dark Matter haloes, which at this scale are now much too small to contain gas or stars. Called dark satellites, these smaller haloes are of course invisible to telescopes, but theory states they should be there.
But proving that these dark satellites are even there requires some evidence of the effect they have on their host galaxies.
Now, thanks to Laura Sales, who is an assistant professor at the University of California, Riverside’s, Department of Physics and Astronomy, and her collaborators at the Kapteyn Astronomical Institute in the Netherlands, Tjitske Starkenberg and Amina Helmi, there is more evidence that these dark satellites are indeed there.
In their paper “Dark influences II: gas and star formation in minor mergers of dwarf galaxies with dark satellites,” from November 2015, they provide an analysis of theory-based computer simulations of the interaction between a dwarf galaxy and a dark satellite.
Their paper shows that when a dark satellite is at its closest point to a dwarf galaxy, the satellite’s gravitational influence compresses the gas in the dwarf. This causes a sustained period of star formation, called a starburst, that can last for billions of years.
Their modelling suggests that dwarf galaxies should be exhibiting a higher rate of star formation than would otherwise be expected. And observation of dwarf galaxies reveals that that is indeed the case. Their modelling also suggests that when a dark satellite and a dwarf galaxy interact, the shape of the dwarf galaxy should change. And again, this is born out by the observation of isolated spheroidal dwarf galaxies, whose origin has so far been a mystery.
The exact nature of Dark Matter is still a mystery, and will probably remain a mystery for quite some time. But studies like this keep shining more light on Dark Matter, and I encourage readers who want more detail to read it.
There are a few places in the Universe that defy comprehension. And supernovae have got to be the most extreme places you can imagine. We’re talking about a star with potentially dozens of times the size and mass of our own Sun that violently dies in a faction of a second.
Faster than it take me to say the word supernova, a complete star collapses in on itself, creating a black hole, forming the denser elements in the Universe, and then exploding outward with the energy of millions or even billions of stars.
But not in all cases. In fact, supernovae come in different flavours, starting from different kinds of stars, ending up with different kinds of explosions, and producing different kinds of remnants.
There are two main types of supernovae, the Type I and the Type II. I know this sounds a little counter intuitive, but let’s start with the Type II first.
These are the supernovae produced when massive stars die. We’ve done a whole show about that process, so if you want to watch it now, you can click here.
But here’s the shorter version.
Stars, as you know, convert hydrogen into fusion at their core. This reaction releases energy in the form of photons, and this light pressure pushes against the force of gravity trying to pull the star in on itself.
Our Sun, doesn’t have the mass to support fusion reactions with elements beyond hydrogen or helium. So once all the helium is used up, the fusion reactions stop and the Sun becomes a white dwarf and starts cooling down.
But if you have a star with 8-25 times the mass of the Sun, it can fuse heavier elements at its core. When it runs out of hydrogen, it switches to helium, and then carbon, neon, etc, all the way up the periodic table of elements. When it reaches iron, however, the fusion reaction takes more energy than it produces.
The outer layers of the star collapses inward in a fraction of a second, and then detonates as a Type II supernova. You’re left with an incredibly dense neutron star as a remnant.
But if the original star had more than about 25 times the mass of the Sun, the same core collapse happens. But the force of the material falling inward collapses the core into a black hole.
Extremely massive stars with more than 100 times the mass of the Sun just explode without a trace. In fact, shortly after the Big Bang, there were stars with hundreds, and maybe even thousands of times the mass of the Sun made of pure hydrogen and helium. These monsters would have lived very short lives, detonating with an incomprehensible amount of energy.
Those are Type II. Type I are a little rarer, and are created when you have a very strange binary star situation.
One star in the pair is a white dwarf, the long dead remnant of a main sequence star like our Sun. The companion can be any other type of star, like a red giant, main sequence star, or even another white dwarf.
What matters is that they’re close enough that the white dwarf can steal matter from its partner, and build it up like a smothering blanket of potential explosiveness. When the stolen amount reaches 1.4 times the mass of the Sun, the white dwarf explodes as a supernova and completely vaporizes.
Because of this 1.4 ratio, astronomers use Type Ia supernovae as “standard candles” to measure distances in the Universe. Since they know how much energy it detonated with, astronomers can calculate the distance to the explosion.
There are probably other, even more rare events that can trigger supernovae, and even more powerful hypernovae and gamma ray bursts. These probably involve collisions between stars, white dwarfs and even neutron stars.
As you’ve probably heard, physicists use particle accelerators to create more massive elements on the Periodic Table. Elements like ununseptium and ununtrium. It takes tremendous energy to create these elements in the first place, and they only last for a fraction of a second.
But in supernovae, these elements would be created, and many others. And we know there are no stable elements further up the periodic table because they’re not here today. A supernova is a far better matter cruncher than any particle accelerator we could ever imagine.
Next time you hear a story about a supernova, listen carefully for what kind of supernova it was: Type I or Type II. How much mass did the star have? That’ll help your imagination wrap your brain around this amazing event.