Posted on by Fraser Cain

Are There Dark Matter Galaxies? ft. Sarah Pearson from Space with Sarah

Dark Matter Galaxies?
Dark Matter Galaxies?


One of the things I love about astronomy is how it’s rapidly changing and evolving over time. Every day there are new discoveries, and advancements in theories that take us incrementally forward in our understanding of the Universe.

One of the best examples of this is dark matter; mysterious and invisible but a significant part of the Universe and accounting for the vast majority of mass out there.

It was first theorized almost 100 years ago when astronomers surveyed the total mass of distant galaxy clusters and found that the visible mass we can see must be just a fraction of the total material in the clusters. When you add up the stars and gas, galaxies move and rotate in ways that indicate there’s a huge halo of invisible matter surrounding it.

Some of the best evidence came from Vera Rubin and Kent Ford in the 60s and 70s, when they measured the rotational velocity of edge-on spiral galaxies. They estimated that there must be about 6 times as much dark matter as regular matter.

This NASA Hubble Space Telescope image shows the distribution of dark matter in the center of the giant galaxy cluster Abell 1689

Dark matter became a serious mystery in astronomy, and many observers and theorists have spent the last half century trying to work out what it is.

And dark matter hasn’t given up its secrets easily. Originally, astronomers thought it might not actually be invisible mass, but a misunderstanding of how gravity works at the largest scales.

But over the last few decades, techniques have been developed, using the gravity of dark matter itself to measure how it bends light from more distant objects. Astronomers don’t know what dark matter is, but they’re able to use it as a telescope. Now that’s impressive.

They’ve found amazing features in the dark matter web out there, vast walls and filaments defining the largest scale structures in the Universe. Clusters where dark matter and its gas have been separated from each other.

Remember, we are at the cutting edge of this mystery, and you’re watching it unfold in real time. 25 years from now, I’m sure we’ll look back at our quaint attempts to understand dark matter.

One of the most interesting questions I have right now is: could there be dark matter galaxies? Completely invisible to our eyes, but able to interact through gravity?

Dark Matter Distribution in Supercluster Abell 901/902

Of course, in times like this, I like to bring in a ringer. Someone who has dedicated their life to the study of these questions.

And today, I’ve got with my Sarah Pearson, a graduate student in astronomy at Columbia University and the host of “Space with Sarah”. Sarah studies the formation and interactions of dwarf galaxies surrounding the Milky Way to understand how galaxies built up at the earliest times in the Universe and form the large galaxies we see at present day.

Fraser: Sarah, welcome to the Guide to Space.

Sarah: Hi Fraser, thanks.

Fraser: Can you talk a little bit about how astronomers map out the distribution of dark matter in the Universe?

Sarah: Yes, definitely. So that is a hard question, as you just explained, we don’t see the dark matter. But one assumption about the Universe we live in is that the light matter or baryonic matter. For example, what you, me and stars consist of, and also galaxies, kind of trace out where the dark matter is located.

So one assumption is that the light matter follows the dark matter. In that way we can actually map out to huge distances, kind of how galaxies and clusters of galaxies are located in our Universe. And we imagine that the dark matter structure is somewhat similar.

Simulation of dark matter. Image credit: NASA

And also recently, very large scale structure simulations of our own Universe have addressed this by kind of starting out with an almost uniform distribution of dark matter in the very early Universe. And what they see is when they let the Universe evolve in time, for example, when the Universe is expanding, you kind of have these dark matter clumps forming into galaxies in all these filaments that you discussed.

You can kind of trace out the location of dark matter by understanding the expansion of space versus gravity that creates the galaxies that we see.

Fraser: And I know in the observations that you see these different distributions of matter and dark matter, it’s not the perfect 1:6 radio that I just mentioned before. You actually see clumping of dark matter that’s sometimes separated from regular matter. So can you actually have whole galaxies that are entirely made of dark matter?

Sarah: Yes, that’s one of the topics I’m super excited about. I work on some of these dark matter only galaxies, and the way you can think about it is that the dark matter is almost uniformly distributed in the early Universe. But some of it is slightly denser than other parts, which collapses down into galaxies. And a lot of those galaxies will actually be a lot smaller than the Milky Way. And because they’re so small, they have a hard time actually holding onto the matter within them.

A bright young star shines Credit: NASA/JPL-Caltech

We think that when star formation turned on in these galaxies, you might actually blow out a lot of the gas that might create more stars, but you won’t blow out the dark matter. That means you could end up with these small tiny galaxies that only have dark matter. They might have some gas, but they’re very hard for us astronomers to find.

Fraser: Well, if they are dark matter, and the dark matter is invisible, how do we find them?

Sarah: Oh, great question. So for example, around our own galaxy Milky Way, it’s hypothesized in our current paradigm of cosmology and the way we think about the Universe, there should actually be thousands of dark matter clumps, these dark matter galaxies, kind of orbiting our own galaxy.

Artist’s impression of dark matter surrounding the Milky Way. (ESO/L. Calçada)

Some of these might be destroyed when they pass through the huge Milky Way disk, that’s one way of destroying them. The smaller ones might be destroyed just by the tides as they orbit around the galaxy. However, we imagine that some of them might survive. Actually they can plough through what we call stellar streams, which are formed when a real galaxy falls into our own Milky Way and tidally stretched out. You should be able to see these density signatures in the stellar stream, and that might indicate what type of dark matter halo that ploughed through them.

Fraser: You hinted at a way that they could form. You’ve got these stars as they’re early forming and blasting themselves apart and the clump of dark matter can’t hold onto them, so that part is gone. Is that the main way these might form, are there other ways you can get these dark galaxies?

Sarah: A different hypothesis is if you have an AGN, an active galactic nuclei within a galaxy from a black hole, you could actually that way blow out a lot of the gas from a galaxy as well. But it’s still not really clear to us astronomers what type of galaxies and if small galaxies would have these active galactic nuclei.

This artist’s impression shows the surroundings of the supermassive black hole at the heart of the active galaxy NGC 3783 in the southern constellation of Centaurus (The Centaur). Credit: ESO/M. Kornmesser

So the best theory right now is that some of them might have attracted a lot of gas initially because they didn’t have a lot of gravity to pull in the gas. But also, because this gas is completely lost. Also from stars exploding, actually, not just from stars turning on initially.

Fraser: And I know that astronomers and physicists are trying to search for dark matter in the Large Hadron Collider, and try to see if they can understand the underlying particle. Does the search that you’re working on give us any sense of that underlying nature of dark matter?

Sarah: Yeah, also a great question, because for example if dark matter is cold. The cold dark matter paradigm is very popular right now. Which states that dark matter might be a very massive weakly interacting particle. When we’re saying warm or cold dark matter, we’re also referring to how fast it’s moving. And depending on what kind of particle dark matter is, that kind of sets the structure for of the early Universe.

So we can start to count, if we have cold dark matter, we would expect to see a certain amount of these cold dark galaxies, where that amount would be different, if we had warm dark matter.

The international Super Cryogenic Dark Matter Search (SuperCDMS) has detected what may be the particle that’s thought to make up dark matter throughout the Universe.

Fraser: That’s really cool, so the observations that you do give the physicists a better idea of what they should be looking for in their particle accelerators, and the two sides can work together. That’s really great.

Okay Sarah, place your bets. What do you think is the most likely candidate for dark matter?

Sarah: I still think this is a hard question, and I’m not sure if the particle physicists yet think we’re helping them. We’re still approaching things from different sides, but we’ll see.

I still think it’s going to be one of those weakly interactive massive particles that we just haven’t detected yet.

Fraser: Thank you so much for joining me on the Guide to Space Sarah, I really appreciate you explaining these dark matter galaxies to us.

Well there you have it. Dark matter is strange, strange stuff. We still don’t know what it is, but we can see how it moves, interacts with matter through its gravity. And we can see how it can form entire galaxies of just dark matter.

A big thanks to Sarah Pearson. If you haven’t already, go and check out her YouTube channel: Space with Sarah. She’s covering big topics, like wondering when the Sun will shut off, how big the Universe is, and how galaxies can collide in an expanding Universe.

Posted on by Matt Williams

The Star That Probably Doesn’t Have an Alien Megastructure (But Maybe it Does) is Dimming Again

Artist's concept of KIC 8462852, which has experienced unusual changes in luminosity over the past few years. Credit: NASA, JPL-Caltech

In September of 2015, scientists announced that the star known as KIC 8462852 (aka. “Tabby’s Star” or “Boyajian’s Star”) was experiencing a strange dip in luminosity. At the time, astronomers indicated that this mysterious behavior could be the result of comets transiting in front of the star, but other (perhaps more hopeful) individuals claimed that it could also be the result of an alien megastructure.

This led to a flurry of studies and articles that sought to offer entirely natural explanations for what has been observed. Even SETI weighed in, indicating that they would begin searching for indications of radio signals coming this mysterious star. But after two years and multiple studies that offer explanations other an alien Dyson Sphere (or some other type of megastructure), the star is at it again! Continue reading “The Star That Probably Doesn’t Have an Alien Megastructure (But Maybe it Does) is Dimming Again”

Posted on by Matt Williams

This is Important! Students Are Figuring Out How to Make Beer on the Moon

A team of UC San Diego students have created an experiment to test if beer can be brewed on the Moon. Credit: NASA

When human beings colonize other Solar bodies, how will they see to their basic needs? Already, research has been performed to determine where colonists would be able to procure water, how they might grow their own food, and where and how they might live. But what about the finer things in life, the things that make all the hard labor and sacrifice worth it? In case it’s not clear yet, I’m talking about beer!

If and when Lunar or Martian colonies become a reality, will the colonists be able to brew and enjoy their own beer? Or will imported beer be the only thing available to them? That’s the question a team of bioengineering students from the University of California San Diego sought to answer. As finalists who competed in the Lab2Moon competition being held by TeamIndus, they combined their love of beer with their love of space exploration.

As the only Indian team in the Google Lunar XPRIZE competition, TeamIndus has been working on a privately-funded spacecraft to send to the Moon. Once complete, TeamIndus hopes to conduct a soft landing on the surface of the Moon later this year. Their accomplishments so far include being one of the five teams selected to compete in the Milestone Prizes and successfully winning the $1 million Milestone Prize for their landing technology.

Johnny Koo, Jared Buchanan, Han Lu Ling, Neeki Ashari, Srivaths Kalyan, and Tavish Traut. Credit: Erik Jepsen/UC San Diego Publications

The Lab2Moon competition was held in order to see a youth experiment brought to the Moon aboard that spacecraft. And while their experiment did not take home the top prize, their final prototype will still be going into space. Thanks to Synergy Moon, who won an XPrize verified launch contract, the experiment will be launched aboard a rocket this December (the planned launch date is currently Dec. 28th, 2017).

For the sake of their experiment, the UC San Diego team – all undergraduates with the Jacobs School of Engineering – sought to test if yeast would be viable in a Lunar environment. As the key ingredient in the production of beer (and many other beneficial things), their experiment sought to determine if Lunar colonists will be capable of becoming their own brewmasters.

Their team name is “Original Gravity”, a delicious pun that alludes to both brewing and the Lunar conditions they are investigating. In the case of brewing, Original Gravity (OG) is the measure of sugars dissolved in the wort (the beer before it is fermented). In the case of the Moon, it refers to the fact that Lunar gravity is just 0.165 times that of Earth’s, which could affect the behavior of the microorganisms like yeast.

As Neeki Ashari, a fifth-year bioengineering student and the team’s PR & Operations Lead, said in a University press release:

“The idea started out with a few laughs amongst a group of friends. We all appreciate the craft of beer, and some of us own our own home-brewing kits. When we heard that there was an opportunity to design an experiment that would go up on India’s moonlander, we thought we could combine our hobby with the competition by focusing on the viability of yeast in outer space.”

With sponsorship from the Omega Yeast Labs, the team designed a unique brewing system. First, all the prep work that precedes the adding of yeast – for instance, combining malted barley and water to create wort – would take place on Earth. Second, the team plans to combine the “fermentation” and “carbonation” phases – which are usually done separately – into one phase.

This process makes for a system that is much easier to design, eliminates the need for releasing accumulated CO² (which can be a hazard) and also prevents the possibility of over-pressurization if anything in the system fails. Last, the testing of fermentation will not rely on density measurements that rely on gravity (as brewers do on Earth), using pressure to determine sugar content instead.

As Han Ling, a fifth-year bioengineering undergraduate student and the team’s leader, explained, “Converting the pressure buildup to fermentation progress is straightforward, as long as volume and original gravity – specific gravity before fermentation, hence our name – are known prior to the experiment.” Measuring roughly as wide as a soda can, their system is able to ferment yeast and worst to create beer, even under Lunar conditions.

In addition to being the first-ever experiment to brew beer in space, their experiment will also be the first to craft beer using such a small apparatus. A Srivaths Kaylan, a fourth-year nano-engineering major and the team’s mechanical lead, indicated:

“Our canister is designed based on actual fermenters. It contains three compartments—the top will be filled with the unfermented beer, and the second will contain the yeast. When the rover lands on the moon with our experiment, a valve will open between the two compartments, allowing the two to mix. When the yeast has done it’s job, a second valve opens and the yeast sink to the bottom and separate from the now fermented beer.”

Team Original Gravity’s revolutionary brewing system. Credit: jacobsschool.ucsd.edu

Looking to the future, Ashari and the team hope to see their experiment adapted for use on other planets – like Mars! Other proposed experiments that were entered in the competition included methods for photosynthesis to producing electricity in a Lunar environment.  Beyond making beer, understanding how yeast will behave in a Lunar environment is also important in the development of pharmaceuticals and yeast-containing foods, such as bread.

It certainly is interesting to think about what kind of beers could be produced in an extra-terrestrial environment, isn’t it? Will future generations of brewers have the option of using locally-grown barley, wheat, hops, and yeast cultures to craft their beer? Will the use of Lunar or Martian water have an effect on the taste of the beer?

And then there’s the matter of names and styles. Will Lunar brewers create a Dark Side of the Moon Stout? Will the people of Mars specialize in Red Ales? Like I said, interesting!

Further Reading: UC San Diego, ABC 10News

Posted on by Matt Williams

Space Station-Based Experiment Might Have Found Evidence of Dark Matter Destroying Itself

The AMS-02 instrument, shown here attached to the outer hull of the ISS. Credit: BASA

Since it was first proposed in the 1960s to account for all the “missing mass” in the Universe, scientists have been trying to find evidence of dark matter. This mysterious, invisible mass theoretically accounts for 26.8% of the baryonic matter (aka. visible matter) out there. And yet, despite almost fifty years of ongoing research and exploration, scientists have not found any direct evidence of this missing mass.

However, according to two new research papers that were recently published in the journal Physical Review Letters, we may have gotten our first glimpse of dark matter thanks to an experiment aboard the International Space Station. Known as the Alpha Magnetic Spectrometer (AMS-02), this a state-of-the-art particle physics detector has been recording cosmic rays since 2011 – which some theorize are produced by the annihilation of dark matter particles.

Like its predecessor (the AMS), the AMS-02 is the result of collaborative work and testing by an international team composed of 56 institutes from 16 countries. With sponsorship from the US Department of Energy (DOE) and overseen by the Johnson Space Center’s AMS Project Office, the AMS-02 was delivered to the ISS aboard the Space Shuttle Endeavour on May 16th, 2011.

Artist’s impression of the AMS-02 instrument. Credit: NASA/JSC

Ostensibly, the AMS-02 is designed to monitor cosmic rays to see how much in the way of antiprotons are falling to Earth. But for the sake of their research, the two science teams also been consulted the data it has been collecting to test theories about dark matter. To break it down, the WIMPs theory of dark matter states that it is made up of Weakly-Interacted Massive Particles (WIMPS), protons and antiprotons are the result of WIMPs colliding.

By monitoring the number of antiprotons that interact with the AMS-02, two science teams (who were working independently of each other) hoped to infer whether or not any of the antiprotons being detected could be caused by WIMP collisions. The difficulty in this, however, is knowing what would constitute an indication, as cosmic rays have many sources and the properties of WIMPs are not entirely defined.

To do this, the two teams developed mathematical models to predict the cosmic ray background, and thus isolate the number of antiprotons that AMS-02 would detect. They further incorporated fine-tuned estimates of the expected mass of the WIMPs, until it fit with the AMS-02 data. One team, led by Alessandro Cuoco, was made up of researchers from the Institute for Theoretical Particle Physics and Cosmology.

Using computer simulations, Cuoco and his colleagues examined the AMS-02 data based on two scenarios – one which accounted for dark matter and one which did not. As they indicate in their study, they not only concluded that the presence of antiprotons created by WIMP collisions better fit the data, but they were also able to constrain the mass of dark matter to about 80 GeV (about 85 times the mass of a single proton or antiproton).

According to supersymmetry, dark-matter particles known as WIMPs annihilate each other, creating a cascade of particles and radiation. Credit: Sky & Telescope / Gregg Dinderman.

As they state in their paper:

“[T]he very accurate recent measurement of the CR antiproton flux by the AMS-02 experiment allows [us] to achieve unprecedented sensitivity to possible DM signals, a factor ~4 stronger than the limits from gamma-ray observations of dwarf galaxies. Further, we find an intriguing indication for a DM signal in the antiproton flux, compatible with the DM interpretation of the Galactic center gamma-ray excess.”

The other team was made up of researchers from the Chinese Academy of Sciences, Nanjing University, the University of Science and Technology of China, and the National Center for Theoretical Sciences. Led by Ming-Yang Cui of Nanjing University, this team made estimates of the background parameters for cosmic rays by using prior data from previous boron-to-carbon ratio and proton measurements.

These measurements, which determine the rate at which boron decays into carbon, can be used to guage the distance that boron molecules travel through space. In this case, they were combined with proton measurements to determine background levels for cosmic rays. They incorporated this data into a Bayesian Analysis framework (i.e. a statistical model used to determine probabilities) to see how many antiprotons could be attributed to WIMP collisions.

The results, as they state it in their paper were quite favorable and produced similar mass estimates to the study led by Cuoco’s team. “Compared with the astrophysical background only hypothesis, we find that a dark matter signal is favored,” they write. “The rest mass of the dark matter particles is ?20 – 80 GeV.”

 

The AMS being delivered to the ISS by the Space Shuttle Endeavour in 2011. Credit: NASA

What’s more, both scientific teams obtained similar estimates when it came to cross-section measurements of dark matter – i.e. the likelihood of collisions happening based on how densely dark matter is distributed. For example, Cuoco’s team obtained a cross-section estimate of 3 x 10-26 per cm³ while Cui’s team obtained an estimate that ranged from 0.2 – 5 × 10-26 per cm³.

The fact that two scientific teams, which were operating independently of each other, came to very similar conclusions based on the same data is highly encouraging. While it is not definitive proof of dark matter, it is certainly a step in the right direction. At best, it shows that we are getting closer to creating a detailed picture of what dark matter looks like.

And in the meantime, both teams acknowledge that further work is necessary. Cuoco and his team also suggest what further steps should be taken. “Confirmation of the signal will require a more accurate study of the systematic uncertainties,” they write, “i.e., the antiproton production cross-section, and the modeling of the effect of solar modulation.”

While scientists have attempted to find evidence of dark matter by monitoring cosmic rays in the past, the AMS-02 stands apart because of its extreme sensitivity. As of May 8th, the spectrometer has conducted measurements on 100 billion particles. As of the penning of this article, that number has increased to over 100,523,550,000!

Further Reading: PBS Nova Next, Ars Technica, Physical Review Letters, (2)

Posted on by Tammy Plotner

The Circinus Constellation

Celestial map of the constellation Circinus, the Pair of Compasses. Credit: Torsten Bronger

Welcome back to Constellation Friday! Today, in honor of the late and great Tammy Plotner, we will be dealing with the compass – the Circinus constellation!

In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the then-known 48 constellations. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively becoming astrological and astronomical canon until the early Modern Age.

Over time, the number of recognized constellations has grown as astronomers and explorers became aware of other stars visible from other location around the world. By the 20th century, the IAU adopted a modern catalog of 88 Constellations. One of these is the Circinus constellation, a small, faint constellation located in the southern skies. It is bordered by the constellations Apus, Centaurus, Lupus, Musca, Norma, Triangulum Australe.

Name and Meaning:

Because Circinus was unknown to the ancient Greeks and Romans, it has no mythology associated with it. The three brightest stars form a narrow triangle. The shape is reminiscent of a drawing (or drafting) compass of the sort used to plot sea and sky charts. Nicolas Louis de Lacaille had a fascination with secular science and the thought of naming a constellation after a science tool fascinated him.

Lacaille’s table, showing his representations of the constellations. Credit: gallica.bnf.fr

In this case, Circinus represents a drafting tool used in navigation, mathematics, technical drawing, engineering drawing, in cartography (drawing maps) – and which many elementary school age children use to learn to draw circles and in geometry to bi-sect lines, draw arcs and so forth. In this case, the device should not be confused with Pyxis, a constellation associated with a ship’s compass… despite the similarity in names with the Latin language!

History of Observation:

The small, faint southern constellation Circinus was created by Nicholas de Lacaille during his stay at the Cape of Good Hope in the mid-18th century. Circinus was given its current name in 1763, when Lacaille published an updated sky map with Latin names for the constellations he introduced.

On the map he created, Lacaille portrayed the constellations of Norma, Circinus, and Triangulum Australe as a set of draughtsman’s instruments – as a ruler, compass, and a surveyor’s level, respectively. This constellation has endured and became one of the 88 modern constellation recognized by the IAU in 1920.

Notable Features:

Circinus has no bright stars and consists of only 3 main stars and 9 Bayer/Flamsteed designated stars. However, the constellation does have several Deep Sky Objects associated with it. For instance, there’s the Circinus Galaxy, a spiral galaxy located approximately 13 million light years distant that was discovered in 1975. The galaxy is notable for the gas rings inside it, one of which is a massive star-forming region, and its black hole-powered core.

Composite image of the central regions of the nearby Circinus galaxy, located about 12 million light years away. Credit: NASA/Chandra/HST

Then there’s the X-ray double star known as Circinus X-1, which is located approximately 30,700 light years away and was discovered in 1969. This system is composed of a neutron star orbiting a main sequence star. Circinus is also home to the bright planetary nebula known as NGC 5315, which was created when a star went supernova and cast off its outer layers into space.

Then there’s NGC 5823 (aka. Caldwell 88), an open cluster located on the border between Circinus and Lupus. Located about 3,500 light years away, this cluster is about 800 million years old and spans about 12 light years.

Finding Circinus:

Circinus is visible at latitudes between +10° and -90° and is best seen at culmination during the month of June. Start by taking out your binoculars for a look at Alpha Circini – a great visual double star. Located about 53.5 light years from Earth, this stellar pair isn’t physically related but does make a unique target. The brighter of the two, Alpha, is a F1 Bright Yellow Dwarf that is a slight variable star. This contrasts very nicely with the fainter, red companion.

For the telescope, take a look at Gamma Circini – a faint star a little over five hundred light years from the Solar System. In the sky, it lies in the Milky Way, between bright Alpha Centauri and the Southern Triangle. Gamma Circini is a binary system, containing a blue giant star with a yellow, F-type, companion. Gamma is unique because it possess a stellar magnetic buoyancy!

Location of the Circinus constellation. Credit: IAU

For larger binoculars and telescopes, have a look at galactic star cluster NGC 5823 (RA 15 : 05.7 Dec -55 : 36). This dim cluster will appear to have several brighter members which are actually foreground stars, but does include Mira-type variable Y Circini. While it will be hard to distinguish from the rich, Milky Way star fields, you will notice an elliptical shaped compression of stars with an asterism which resembles and open umbrella.

For large telescopes, check out ESO 97-G13 – the “Circinus Galaxy”. Located only 4 degrees below the Galactic plane, and 13 million light-years away (RA 14h 13m 9.9s Dec 65° 20? 21?), this Seyfert Galaxy is undergoing tumultuous changes, as rings of gas are being ejected from the galactic core. While it can be spotted in a small telescope, science didn’t notice it until 25 years ago!

We have written many interesting articles about the constellation here at Universe Today. Here is What Are The Constellations?, What Is The Zodiac?, and Zodiac Signs And Their Dates.

Be sure to check out The Messier Catalog while you’re at it!

For more information, check out the IAUs list of Constellations, and the Students for the Exploration and Development of Space page on Canes Venatici and Constellation Families.

Sources:

Posted on by Matt Williams

It’s Been Three Years Since We’ve Had a Supernova This Close

Artistic impression of a star going supernova, casting its chemically enriched contents into the universe. Credit: NASA/Swift/Skyworks Digital/Dana Berry

A supernova is one of the most impressive astronomical events anyone can possibly witness. Characterized by a massive explosion that takes place during the final stages of a massive star’s life (after billions of years of evolution), this sort of event is understandably quite rare. In fact, within the Milky Way Galaxy, a supernova event is likely to happen just once a century.

But within the Fireworks Galaxy (aka. the spiral galaxy NGC 6946), which is located 22 million light years from Earth and has half as many stars as our galaxy, supernovae are about ten times more frequent. On May 13th, while examining this galaxy from his home in Utah, amateur astronomer Patrick Wiggins spotted what was later confirmed to be a Type II supernova.

To break this magnificent astronomical event down, most supernova can be placed into two categories. Type I Supernovae occur when a smaller star has consumed all of its nuclear fuel, and then undergoes core collapse with the help of additional matter accreted from a nearby orbiting star. Type II Supernovae are the result of massive stars undergoing core collapse all on their own.

The confirmed supernova, “SN 2017aew”, which can be seen on the top right side of the “Fireworks Galaxy”. Click to see animation. Credit: Patrick Wiggins

In both cases, the result is a sudden and extreme increase in brightness, where the star blows off its outer layers and may become temporarily brighter than all the other stars in its galaxy. It then spends the next few months slowly fading until it becomes a white dwarf. It was while surveying the Fireworks galaxy with his own telescope that Wiggins noticed such a sudden burst in brightness, which had not been there just two nights before.

Wiggins finding was confirmed a day later (May 14th) by two experts in supernovae – Subo Dong and Krzysztof Z. Stanek, two professors from Peking University and Ohio State University, respectively. After conducting observations of their own, they determined that what Wiggins had witnessed was a Type II supernova, which has since been designated as SN 2017eaw.

In addition to being an amateur astronomer, Patrick Wiggins is also the public outreach educator for the University of Utah’s Department of Physics & Astronomy and the NASA Solar System Ambassador to Utah. This supernova, which was the third Wiggins has observed in his lifetime, is also the closest to Earth in three years, being about 22 million light years from Earth.

The last time a supernova was observed exploding this close to Earth was on January 22nd, 2014. At the time, students at the University of London Observatory spotted an exploding star (SN 2014J) in the nearby Cigar Galaxy (aka. M82), which is located around 12 million light years away. This was the closest supernova to be observed in recent decades.

Animation showing a comparison between M82 on Jan. 22nd, 2014 Nov. 22nd, 2013. Credit: E. Guido/N. Howes/M. Nicolini

As such, the observation of a supernova at a comparatively close distance to Earth just three years later is a pretty impressive feat. And it is an additional feather in the cap of an amateur astronomer whose resume is already quite impressive! Besides the three supernova he was observed, Wiggins has received many accolades over the years for his contributions to astronomy.

These include the Distinguished Public Service Medal, which is the highest civilian honor NASA can bestow. In addition, he discovered an asteroid in 2008 which the IAU – at Wiggin’s request – officially named “Univofutah”, in honor of the University of Utah. He is also a member of the Phun with Physics team, which provides free scientific lessons at the Natural History Museum of Utah.

Further Reading: University of Utah UNews

Posted on by Fraser Cain

Weekly Space Hangout – May 19, 2017: Eric Fisher of Labfundr

Host: Fraser Cain (@fcain)

Special Guest:
Eric Fisher is the head of Labfundr, a Canadian crowdsourcing platform for science research and outreach. Eric is an entrepreneur, recovering biochemist, and son of a glaciologist. He completed a PhD in Biochemistry & Molecular Biology at Dalhousie University in Halifax, Nova Scotia, Canada. At Dalhousie, Eric investigated how liver cells create and destroy “bad” cholesterol particles. Eric recently founded Labfundr, Canada’s first crowdfunding platform for science, which aims to boost public engagement and investment in research. He stays on his toes by trying to keep up with his dog Joni, who is smarter and faster than him.

Guests:
Dr. Kimberly Cartier ( KimberlyCartier.org / @AstroKimCartier )
Dr. Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg ChartYourWorld.org)
Alessondra Springmann (@sondy)
Their stories this week:

Explaining massive black hole formation with LIGO

Discovery of a moon around large dwarf planet

More troubles for SLS and here

A Neptune-sized planet that looks like a Jupiter

Rivers on Titan look more like Mars than Earth

We use a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

Announcements:

The WSH recently welcomed back Mathew Anderson, author of “Our Cosmic Story,” to the show to discuss his recent update. He was kind enough to offer our viewers free electronic copies of his complete book as well as his standalone update. Complete information about how to get your copies will be available on the WSH webpage – just visit http://www.wsh-crew.net/cosmicstory for all the details.

If you’d like to join Fraser and Paul Matt Sutter on their Tour to Iceland in February 2018, you can find the information at astrotouring.com.

If you would like to join the Weekly Space Hangout Crew, visit their site here and sign up. They’re a great team who can help you join our online discussions!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Universe Today, or the Universe Today YouTube page

Posted on by Ken Kremer

We Will Launch on Reusable Rocket After Exceptional SpaceX Performance – Inmarsat CEO Tells Universe Today

All 9 Merlin 1D first stage engines firing beautifully as SpaceX Falcon 9 arcs over down range successfully carrying Inmarsat 5F4 #I5F4 to geostationary transfer orbit at twilight after liftoff from Launch Complex 39A on 15 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com

All 9 Merlin 1D first stage engines firing beautifully as SpaceX Falcon 9 arcs over down range successfully carrying Inmarsat 5F4 #I5F4 to geostationary transfer orbit at twilight after liftoff from Launch Complex 39A on 15 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com

KENNEDY SPACE CENTER, FL – Following SpaceX’s “exceptional performance” launching an immensely powerful broadband satellite on their maiden mission for Inmarsat this week on a Falcon 9 rocket, the company CEO told Universe Today that Inmarsat was willing to conduct future launches with SpaceX – including on a “reusable rocket in the future!”

“This has obviously been an absolutely exceptional performance from SpaceX, Inmarsat CEO Rupert Pearce told Universe Today in a post launch interview at the Kennedy Space Center on Monday, May 15.

“They have now earned themselves an immensely loyal customer.”

SpaceX is the first and thus far only company in history to successfully recover and refly a previously flown orbit class ‘flight-proven’ liquid fueled first stage rocket – during the SES-10 launch in March 2017.

The twilight blastoff of the SpaceX Falcon 9 carrying the Inmarsat-5 Flight 4 communications satellite for commercial High-Speed mobile broadband provider Inmarsat occurred at 7:21 p.m. EDT (or 23:21 UTC) on Monday evening, May 15, from SpaceX’s seaside Launch Complex 39A on NASA’s Kennedy Space Center in Florida.

“They hit the ball out of the park with this launch for us,” Inmarsat CEO Pearce told me regarding the new space company founded by billionaire CEO Elon Musk.

The never before used 229-foot-tall (70-meter) SpaceX Falcon 9 successfully delivered the gigantic bus sized 6100 kg Inmarsat-5 F4 satellite to a Geostationary Transfer Orbit (GTO) under brilliant blue and nearly cloudless twilight skies from the Florida Space Coast. Read my launch report here.

The first stage is powered by nine Merlin 1 D engines fueled by RP-1 and liquid oxygen propellants and generating 1.7 million pounds.

SpaceX Falcon 9 rocket carrying commercial Inmarsat 5 F4 broadband satellite blasts off to geostationary orbit at twilight at 7:20 p.m. EDT from Launch Complex 39A on 15 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com

The Inmarsat-5 F4 satellite is designed to provide high speed broad band service to government, military, maritime and aviation users and ship and airplane customers numbering in the millions to tens of millions of customers now and potentially hundreds of millions of customers in the future. It was the heaviest payload ever launched by a Falcon 9.

Pearce says he “has every confidence in SpaceX.”

Inmarsat is a leading provider of mobile satellite communications, providing global connectivity more than 35 years – on land, at sea and in the air, says the firm.

I asked CEO Pearce; What does the future hold regarding further Inmarsat launches with SpaceX?

“They [SpaceX] have now just gained and earned themselves an immensely loyal customer [from Inmarsat], CEO Pearce replied.

“We will be looking to do further launches with them.”

The 7 meter long Inmarsat-5 F4 satellite was deployed approximately 32 minutes after Monday’s launch when it will come under the command of the Boeing and Inmarsat satellite operations teams based at the Boeing facility in El Segundo.

Would you consider a used rocket, a previously flown booster?

“I’m sure we will be using a ‘reused rocket’, Pearce stated. “And we will be launching on a ‘reusable rocket’ in the future.”

“We will be looking to support them in any way we can with their new innovation programs.”

Blastoff of SpaceX Falcon 9 rocket at 7:20 p.m. EDT from Launch Complex 39A on 15 May 2017 from NASA’s Kennedy Space Center in Florida which successfully delivered Inmarsat-5 F4 broadband satellite to orbit. Credit: Julian Leek

In contrast to virtually all Falcon 9 launches in the past 18 months, no attempt was made to recover the first stage booster.

For this launch there was basically no choice but to make the first stage ‘expendable’ because Inmarsat-5 F4 is heaviest ever payload launched on a Falcon 9.

The satellites heavy weight with a launch mass of approx. 6,100 kg (13,400 lbs) means the rocket needs all its thrust to get the satellite to orbit and thus precludes the chance to land the first stage at sea or land.

Thus there are no landing legs or grid gins attached to the skin of this Falcon 9.

“This rocket that went today was not reusable. That was just a creature of its time,” Pearce elaborated.

“We will stay at the cutting edge with SpaceX!”

To date, SpaceX has successfully recovered 10 first stage boosters either by land or by sea on an ocean going platform.

Inmarsat CEO Rupert Pierce during post launch interview with Ken Kremer/Universe Today discusses SpaceX Falcon 9 launch carrying commercial Inmarsat 5 F4 broadband satellite to geostationary orbit after liftoff at 7:20 p.m. EDT from Launch Complex 39A on 15 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com

The Inmarsat-5 F4 (I-5 F4) will become part of the firms Global Xpress network “which has been delivering seamless, high-speed broadband connectivity across the world since December 2015,” says Inmarsat.

“Once in geostationary orbit, the satellite will provide additional capacity for Global Xpress users on land, at sea and in the air.”

SpaceX Falcon 9 deploys quartet of landing legs moments before precision propulsive ground touchdown at Landing Zone 1 on Canaveral Air Force Station barely nine minutes after liftoff from Launch Complex 39A on 1 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com

I-5 F4 was built by Boeing at their satellite operations facility in El Segundo, CA for Inmarsat.

The new satellite will join 3 others already in orbit.

Inmarsat has invested approximately US$1.6 billion in the Global Xpress constellation “to establish the first ever global Ka-band service from a single network operator.”

SpaceX Falcon 9 rocket carrying commercial Inmarsat 5 F4 broadband satellite accelerates to orbit leaving exhaust trail in its wake after twilight launch at 7:20 p.m. EDT from Launch Complex 39A on 15 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com

Inmarsat 5 F4 counts as the sixth SpaceX launch of 2017.

And SpaceX is on an absolutely torrid launch pace. Monday’s liftoff comes just 2 weeks after the last successful SpaceX Falcon 9 liftoff on May 1 of the super secret NROL-76 payload for the National Reconnaissance Office, or NRO – as I reported here.

Watch for Ken’s continuing onsite launch reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station in Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

SpaceX Falcon 9 Inmarsat-5 F4 (I-5 F4) mission artwork. Credit: SpaceX/Inmarsat

Inmarsat-5 Flight 4 (I-5 F4) satellite undergoes prelaunch processing for liftoff on SpaceX Falcon 9. Credit: Inmarsat

SpaceX Falcon 9 rocket carrying commercial Inmarsat 5 F4 broadband satellite blasts off to geostationary orbit at twilight at 7:20 p.m. EDT from Launch Complex 39A on 15 May 2017 from NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/Kenkremer.com

Posted on by Evan Gough

Dinosaur Killing Asteroid Hit in Exactly the Wrong Place

When an asteroid struck the Yucatan region about 66 million years ago, it triggered the extinction of the dinosaurs. ESA's Hera mission is visiting the smallest spacerock ever as part of our effort to not get creamed by an asteroid. Credit: NASA/Don Davis
When an asteroid struck the Yucatan region about 66 million years ago, it triggered the extinction of the dinosaurs. ESA's Hera mission is visiting the smallest spacerock ever as part of our effort to not get creamed by an asteroid. Credit: NASA/Don Davis

The asteroid that struck Earth about 66 million years ago and led to the mass extinction of dinosaurs may have hit one of the worst places possible as far as life on Earth was concerned. When it struck, the resulting cataclysm choked the atmosphere with sulphur, which blocked out the Sun. Without the Sun, the food chain collapsed, and it was bye-bye dinosaurs, and bye-bye most of the other life on Earth, too.

But, as it turns out, if it had struck a few moments earlier or later, it would not have hit the Yucatan, and things may have turned out differently. Why? Because of the concentration of the mineral gypsum in that area.

The place where the asteroid hit Earth is called the Chicxulub Crater, and scientists have been studying that area to try to learn more about the impact event that altered the course of life on Earth. An upcoming BBC documentary called “The Day The Dinosaurs Died,” focuses on what happened when the asteroid struck. Drill-core samples from the Yucatan area help explain the events that followed the impact.

The drilling rig off the coast of the Yucatan. The rig was there in the Spring of 2016 obtaining samples from the seafloor. Image: BBC/Barcroft Productions.
The drilling rig off the coast of the Yucatan. The rig was there in the Spring of 2016 obtaining samples from the seafloor. Image: BBC/Barcroft Productions.

The core samples, which are from as deep as 1300 m beneath the Gulf of Mexico, are from a feature called the peak ring.

When the asteroid struck Earth, it excavated a crater 100 km across and 30 km deep. This crater collapsed into a wider but shallower crater 200 km across and a few km deep. Then the center of the crater rebounded, and collapsed again, leaving the peak ring feature. The Chicxulub crater is now partly under water, and that’s where a drilling rig was set up to take samples.

The peak ring is at the center of the crater, offshore of the Yucatan Peninsula. Image: NASA/BBC
The peak ring is at the center of the crater, offshore of the Yucatan Peninsula. Image: NASA/BBC

The core samples revealed rock that has been heavily fractured and altered by immense pressures. The same impact that altered those rocks would have generated an enormous amount of heat, and that heat created an enormous cloud of sulphur from the vaporized gypsum. That cloud persisted, which led to a global winter. Temperatures dropped, plant growth came to a standstill, and the course of events on Earth were altered forever.

“Had the asteroid struck a few moments earlier or later, rather than hitting shallow coastal waters it might have hit deep ocean,” documentary co-presenter Ben Garrod told the BBC.

“This is where we get to the great irony of the story – because in the end it wasn’t the size of the asteroid, the scale of blast, or even its global reach that made dinosaurs extinct – it was where the impact happened,” said Ben Garrod, who presents “The Day The Dinosaurs Died” with Alice Roberts.

“An impact in the nearby Atlantic or Pacific oceans would have meant much less vaporised rock – including the deadly gypsum. The cloud would have been less dense and sunlight could still have reached the planet’s surface, meaning what happened next might have been avoided,” said Garrod.

In the documentary, host Alice Roberts will also visit a quarry in New Jersey, where fossil evidence shows a massive die-off in a very short period of time. In fact, these creatures could have died on the very day that the asteroid struck.

The core samples from the drilling rig show rocks that were subjected to immense heat and pressure at the time of the impact. Image: Barcroft Productions/BBC
The core samples from the drilling rig show rocks that were subjected to immense heat and pressure at the time of the impact. Image: Barcroft Productions/BBC

“All these fossils occur in a layer no more than 10cm thick,” palaeontologist Ken Lacovara tells Alice. “They died suddenly and were buried quickly. It tells us this is a moment in geological time. That’s days, weeks, maybe months. But this is not thousands of years; it’s not hundreds of thousands of years. This is essentially an instantaneous event.”

There’s lots of evidence showing that an asteroid struck Earth about 66 million years ago, causing widespread extinction. NASA satellite images clearly show crater features, now obscured by 66 million years of geological activity, but still visible.

There’s also what’s called the K-T Boundary, or Cretaceous-Tertiary Boundary. It’s a geological signature dating to 66 million years ago, which marks the end of the Cretaceous Period. In that boundary is a layer of iridium at very high concentrations, much higher than is normally present in the Earth’s crust. Since iridium is much more abundant in asteroids, the conclusion is that it was probably deposited by an asteroid.

But this is the first evidence that shows how critical the actual location of the event may have been. If it had not struck where it had, dinosaurs may never have gone extinct, you and I would not be here, and things on Earth could look much different.

It might sound like the stuff of science fiction, but who knows? Maybe a race of intelligent lizards might already have mastered interstellar travel.