Our Sun in all its intense, energetic glory. When life appeared on Earth, the Sun would have been much different than it is now; a more intense, energetic neighbor. Image: NASA/SDO.
The early Solar System was a much different place than it is now. Chaos reigned supreme before things settled down into their present state. New research shows that the young Sun was more chaotic and expressive than it is now, and that Earth’s magnetic field was key for the development of life on Earth.
Researchers at the Harvard Smithsonian Centre for Astrophysics have been studying a star called Kappa Ceti, about 30 light years away in the Cetus constellation. Kappa Ceti is in many ways similar to our own Sun, but it’s estimated to be between 400 million to 600 million years old, about the same age as our Sun when life appeared on Earth. Studying Kappa Ceti gives scientists a good idea of the type of star that early life on Earth had to contend with.
Kappa Ceti, at its young age, is much more magnetically active than our 4.6 billion year old Sun, according to this new research. It emits a relentless solar wind, which the research team at Harvard says is 50 times as powerful as the solar wind from our Sun. It’s surface is also much more active and chaotic. Rather than the sunspots that we can see on our Sun, Kappa Ceti displays numerous starspots, the larger brother of the sunspot. And the starspots on Kappa Ceti are much more numerous than the sunspots observed on the Sun.
We’re familiar with the solar flares that come from the Sun periodically, but in the early life of the Sun, the flares were much more energetic too. Researchers have found evidence on Kappa Ceti of what are called super-flares. These monsters are similar to the flares we see today, but can release 10 to 100 million times more energy than the flares we can observe on our Sun today.
So if early life on Earth had to contend with such a noisy neighbour for a Sun, how did it cope? What prevented all that solar output from stripping away Earth’s atmosphere, and killing anything alive? Then, as now, the Earth’s electromagnetic field protected it. But in the same way that the Sun was so different long ago, so was the Earth’s protective shield. It may have been weaker than it is now.
The researchers found that if the Earth’s magnetic field was indeed weaker, then the magnetosphere may have been only 34% to 48% as large as it is now. The conclusion of the study says “… the early magnetic interaction between the stellar wind and the young Earth planetary magnetic field may well have prevented the volatile losses from the Earth exosphere and created conditions to support life.”
Or, in plain language: “The early Earth didn’t have as much protection as it does now, but it had enough,” says Do Nascimento.
Dark matter is invisible. Based on the effect of gravitational lensing, a ring of dark matter has been inferred in this image of a galaxy cluster (CL0024+17) and has been represented in blue. Image: NASA/ESA.
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.
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.
NGC 5253 is one of the nearest of the known Blue Compact Dwarf (BCD) galaxies, and is located at a distance of about 12 million light-years from Earth in the southern constellation of Centaurus. It is experiencing a starburst of hot, young stars, which could be caused by dark satellites. Image: NASA/ESA/Hubble.
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.
Comet Siding Spring (C/2007 Q3) as imaged in the infrared by the WISE space telescope. The image was taken January 10, 2010 when the comet was 2.5AU from the Sun. Credit: NASA/JPL-Caltech/UCLA
In the Autumn of 2014, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft arrived at Mars and entered into orbit. MAVEN wasn’t the only visitor to arrive at Mars at that time though, as comet Siding Spring (C/2013 A1) also showed up at Mars. Most of MAVEN’s instruments were shut down to protect sensitive electronics from Siding Spring’s magnetic field. But the magnetometer aboard the spacecraft was left on, which gave MAVEN a great view of the interaction between the planet and the comet.
Unlike Earth, which has a powerful magnetosphere created by its rotating metal core, Mars’ magnetosphere is created by plasma in its upper atmosphere, and is not very powerful. (Mars may have had a rotating metal core in the past, and a stronger magnetosphere because of it, but that’s beside the point.) Comet Siding Spring is small, with its nucleus being only about one half a kilometer. But its magnetosphere is situated in its coma, the long ‘tail’ of the comet that stretches out for a million kilometers.
When Siding Spring approached Mars, it came to within 140,000 km (87,000 miles) of the planet. But the comet’s coma nearly touched the surface of the planet, and during that hours-long encounter, the magnetic field from the comet created havoc with Mars’ magnetic field. And MAVEN’s magnetometer captured the event.
MAVEN was in position to capture the close encounter between Mars and comet Siding Spring. Image: NASA/Goddard.
Jared Espley is a member of the MAVEN team at Goddard Space Flight Center. He said of the Mars/Siding Spring event, “We think the encounter blew away part of Mars’ upper atmosphere, much like a strong solar storm would.”
“The main action took place during the comet’s closest approach,” said Espley, “but the planet’s magnetosphere began to feel some effects as soon as it entered the outer edge of the comet’s coma.”
Espley and his colleagues describe the event as a tide that washed over the Martian magnetosphere. Comet Siding Spring’s tail has a magnetosphere due to its interactions with the solar wind. As the comet is heated by the sun, plasma is generated, which interacts in turn with the solar wind, creating a magnetosphere. And like a tide, the effects were subtle at first, and the event played out over several hours as the comet passed by the planet.
Siding Spring’s magnetic tide had only a subtle effect on Mars at first. Normally, Mars’ magnetosphere is situated evenly around the planet, but as the comet got closer, some parts of the planet’s magnetosphere began to realign themselves. Eventually the effect was so powerful that the field was thrown into chaos, like a flag flapping every which way in a powerful wind. It took Mars a while to recover from this encounter as the field took several hours to recover.
MAVEN’s task is to gain a better understanding of the interactions between the Sun’s solar wind and Mars. So being able to witness the effect that Siding Spring had on Mars is an added bonus. Bruce Jakosky, from the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder, is one of MAVEN’s principal investigators. “By looking at how the magnetospheres of the comet and of Mars interact with each other,” said Jakosky, “we’re getting a better understanding of the detailed processes that control each one.”
An artist's impression of a Gamma Ray Burst. Credit: Stanford.edu
Last week’s announcement that Gravitational Waves (GW) have been detected for the first time—as a result of the merger of two black holes—is huge news. But now a Gamma Ray Burst (GRB) originating from the same place, and that arrived at Earth 0.4 seconds after the GW, is making news. Isolated black holes aren’t supposed to create GRB’s; they need to be near a large amount of matter to do that.
NASA’s Fermi telescope detected the GRB, coming from the same point as the GW, a mere 0.4 seconds after the waves arrived. Though we can’t be absolutely certain that the two phenomena are from the same black hole merger, the Fermi team calculates the odds of that being a coincidence at only 0.0022%. That’s a pretty solid correlation.
So what’s going on here? To back up a little, let’s look at what we thought was happening when LIGO detected gravitational waves.
Our understanding was that the two black holes orbited each other for a long time. As they did so, their massive gravity would have cleared the area around them of matter. By they time they finished circling each other and merged, they would have been isolated in space. But now that a GRB has been detected, we need some way to account for it. We need more matter to be present.
According to Abraham Loeb, of Harvard University, the missing piece of this puzzle is a massive star—itself the result of a binary star system combining into one—a few hundred times larger than the Sun, that spawned two black holes. A star this size would form a black hole when it exhausted its fuel and collapsed. But why would there be two black holes?
Again, according to Loeb, if the star was rotating at a high enough rate—just below its break up frequency—the star could actually form two collapsing cores in a dumbbell configuration, and hence two black holes. But now these two black holes would not be isolated in space, they would actually be inside a massive star. Or what was left of one. The remnants of the massive star is the missing matter.
When the black holes joined together, an outflow would be generated, which would produce the GRB. Or else the GRB came “from a jet originating out of the accretion disk of residual debris around the BH remnant,” according to Loeb’s paper. So why the 0.4 s delay? This is the time it took the GRB to cross the star, relative to the gravitational waves.
It sounds like a nice tidy explanation. But, as Loeb notes, there are some problems with it. The main question is, why was the GRB so weak, or dim? Loeb’s paper says that “observed GRB may be just one spike in a longer and weaker transient below the GBM detection threshold.”
But was the GRB really weak? Or was it even real? The European Space Agency has their own gamma ray detecting spacecraft, called Integral. Integral was not able to confirm the GRB signal, and according to this paper, the gamma ray signal was not real after all.
China's new radio telescope, the world's largest, should be completed by September 2016. Image: FAST
China is building the world’s largest radio telescope, and will have to move almost 10,000 people from the vicinity to guarantee the telescope’s effectiveness. The telescope, called the Five-hundred-meter Aperture Spherical Telescope (FAST), will be completed in September, 2016. At 500 meters in diameter, it will surpass the workhorse Arecibo radio observatory in Puerto Rico, which is 305 meters in diameter.
China has routinely moved large amounts of people to make room for developments like the Three Gorges Dam. But in this case, the people are being moved so that FAST can have a five kilometre radio-quiet buffer around it.
According to China’s news agency Xinhua, an unnamed official said the people are being moved so that the facility can have a “sound electromagnetic wave environment.” Common devices and equipment like microwave ovens, garage door openers, and of course, mobile phones, all create radio waves that FAST will sense and which can interfere with the telescope’s operation.
The telescope’s high level of sensitivity “will help us to search for intelligent life outside of the galaxy,” according to Wu Xiangping, director-general of the Chinese Astronomical Society. But aside from searching for radio waves that could be from distant alien civilizations, like SETI does, the enormous dish will also to be used to study astronomical objects that emit radio signals, like galaxies, pulsars, quasars, and supernovae. The radio signals from these objects can tell us about their mass, and their distance from us. But the signals are very weak, so radio telescopes have to be huge to be effective.
Radio telescopes are also used to send out radio signals and bounce them off objects like asteroids and the other planets in our Solar System. These signals are detected by the telescope when they return to Earth, and used to create images.
Huge radio telescopes like FAST can only be built in certain places. They require a large, naturally dish-shaped area for construction. (Arecibo is built in a huge karst sinkhole in Puerto Rico.) Though FAST is in a fairly remote location, where there are no major cities or towns, there are still approximately 10,000 people who will have to be moved. Most of the people moved will be compensated to the tune of $2500, with some receiving more than that.
The FAST facility is part of a concerted effort by China to be a dominant player in space study and exploration. The Chang e 3 mission to the Moon, with its unmanned lander and rover, showed China’s growing capabilities in space. China also plans to have its own space station, its own space weather station at LaGrange 1, and a mission to Mars by 2020, consisting of an orbiter and a rover.
Construction on FAST began in 2011, and will cost 1.2 billion yuan ($260 million) to build.
This overhead shot of the James Webb Space Telescope shows part of the installation of the 18 primary flight mirrors onto the telescope structure in a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Credits: NASA’s Goddard Space Flight Center/Chris Gunn
See time-lapse video below
This overhead shot of the James Webb Space Telescope shows part of the installation of the 18 primary flight mirrors onto the telescope structure in a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Credits: NASA’s Goddard Space Flight Center/Chris Gunn See time-lapse video below
NASA GODDARD SPACE FLIGHT CENTER, MD – A time-lapse video newly released by NASA documents the painstakingly complex assembly of the primary mirror at the heart of the biggest space telescope ever conceived by humankind – NASA’s James Webb Space Telescope (JWST).
Full panoramic view of the constellations near the Milky Way by Matt Dieterich
What comes to mind when you look up at the night sky and spot the constellations? Is it a grand desire to explore deep into space? Is it the feeling of awe and wonder, that perhaps these shapes in the sky represent something? Or is the sense that, like countless generations of human beings who have come before you, you are staring into the heavens and seeing patterns? If the answer to any of the above is yes, then you are in good company!
While most people can name at least one constellation, very few know the story of where they came from. Who were the first people to spot them? Where do their names come from? And just how many constellations are there in the sky? Here are a few of the answers, followed by a list of every known constellation, and all the relevant information pertaining to them.
Definition:
A constellation is essentially a specific area of the celestial sphere, though the term is more often associated with a chance grouping of stars in the night sky. Technically, star groupings are known as asterisms, and the practice of locating and assigning names to them is known as asterism. This practice goes back thousands of years, possibly even to the Upper Paleolithic. In fact, archaeological studies have identified markings in the famous cave paintings at Lascaux in southern France (ca. 17,300 years old) that could be depictions of the Pleiades cluster and Orion’s Belt.
There are currently 88 officially recognized constellations in total, which together cover the entire sky. Hence, any given point in a celestial coordinate system can unambiguously be assigned to a constellation. It is also a common practice in modern astronomy, when locating objects in the sky, to indicate which constellation their coordinates place them in proximity to, thus conveying a rough idea of where they can be found.
Closeup of the Lascaux cave paintings, showing a bull and what could be the Pleiades Cluster (over the right shoulder) and Orion’s Belt (far left). Credit: ancient-wisdom.com
The word constellation has its roots in the Late Latin term constellatio, which can be translated as “set of stars”. A more functional definition would be a recognizable pattern of stars whose appearance is associated with mythical characters, creatures, or certain characteristics. It’s also important to note that colloquial usage of the word “constellation” does not generally differentiate between an asterism and the area surrounding one.
Typically, stars in a constellation have only one thing in common – they appear near each other in the sky when viewed from Earth. In reality, these stars are often very distant from each other and only appear to line up based on their immense distance from Earth. Since stars also travel on their own orbits through the Milky Way, the star patterns of the constellations change slowly over time.
History of Observation:
It is believed that since the earliest humans walked the Earth, the tradition of looking up at the night sky and assigning names and characters to them existed. However, the earliest recorded evidence of asterism and constellation-naming comes to us from ancient Mesopotamia, and in the form of etchings on clay tablets that are dated to around ca. 3000 BCE.
However, the ancient Babylonians were the first to recognize that astronomical phenomena are periodic and can be calculated mathematically. It was during the middle Bronze Age (ca. 2100 – 1500 BCE) that the oldest Babylonian star catalogs were created, which would later come to be consulted by Greek, Roman and Hebrew scholars to create their own astronomical and astrological systems.
Star map showing the celestial globe of Su Song (1020-1101), a Chinese scientist and mechanical engineer of the Song Dynasty (960-1279). Credit: Wikipedia Commons
In ancient China, astronomical traditions can be traced back to the middle Shang Dynasty (ca. 13th century BCE), where oracle bones unearthed at Anyang were inscribed with the names of star. The parallels between these and earlier Sumerian star catalogs suggest they did no arise independently. Astronomical observations conducted in the Zhanguo period (5th century BCE) were later recorded by astronomers in the Han period (206 BCE – 220 CE), giving rise to the single system of classic Chinese astronomy.
In India, the earliest indications of an astronomical system being developed are attributed to the Indus Valley Civilization (3300–1300 BCE). However, the oldest recorded example of astronomy and astrology is the Vedanga Jyotisha, a study which is part of the wider Vedic literature (i.e. religious) of the time, and which is dated to 1400-1200 BCE.
By the 4th century BCE, the Greeks adopted the Babylonian system and added several more constellations to the mix. By the 2nd century CE, Claudius Ptolemaus (aka. Ptolemy) combined all 48 known constellations into a single system. His treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come.
Between the 8th and 15th centuries, the Islamic world experienced a burst of scientific development, reaching from the Al-Andus region (modern-day Spain and Portugal) to Central Asia and India. Advancements in astronomy and astrology closely paralleled those made in other fields, where ancient and classical knowledge was assimilated and expanded on.
The Northern Constellations. Credit: Bodel Nijenhuis Collection/Leiden University Library
In turn, Islamic astronomy later had a significant influence on Byzantine and European astronomy, as well as Chinese and West African astronomy (particularly in the Mali Empire). A significant number of stars in the sky, such as Aldebaran and Altair, and astronomical terms such as alidade, azimuth, and almucantar, are still referred to by their Arabic names.
From the end of the 16th century onward, the age of exploration gave rise to circumpolar navigation, which in turn led European astronomers to witness the constellations in the South Celestial Pole for the first time. Combined with expeditions that traveled to the Americas, Africa, Asia, and all other previously unexplored regions of the planet, modern star catalogs began to emerge.
IAU Constellations:
The International Astronomical Union (IAU) currently has a list of 88 accepted constellations. This is largely due to the work of Henry Norris Russell, who in 1922, aided the IAU in dividing the celestial sphere into 88 official sectors. In 1930, the boundaries between these constellations were devised by Eugène Delporte, along vertical and horizontal lines of right ascension and declination.
The IAU list is also based on the 48 constellations listed by Ptolemy in his Almagest, with early modern modifications and additions by subsequent astronomers – such as Petrus Plancius (1552 – 1622), Johannes Hevelius (1611 – 1687), and Nicolas Louis de Lacaille (1713 – 1762).
The modern constellations, color-coded by family, with a dotted line denoting the ecliptic. Credit: NASA/Scientific Visualization Studio
However, the data Delporte used was dated to the late 19th century, back when the suggestion was first made to designate boundaries in the celestial sphere. As a consequence, the precession of the equinoxes has already led the borders of the modern star map to become somewhat skewed, to the point that they are no longer vertical or horizontal. This effect will increase over the centuries and will require revision.
Not a single new constellation or constellation name has been postulated in centuries. When new stars are discovered, astronomers simply add them to the constellation they are closest to. So consider the information below, which lists all 88 constellations and provides information about each, to be up-to-date! We even threw in a few links about the zodiac, its meanings, and dates.
A jet of material being ejected out of a black hole at the centre of the galaxy BL Lacertae. Image: Dr. Jose L. Gomez
What do you get when you combine 15 radio telescopes on Earth and one in space? You get an enormous “virtual telescope” that is 63,000 miles across. And when you point it at a distant black hole, you get the highest resolution image every seen in astronomy.
Although it looks just like a big green blob, it’s actually an enormously energetic jet of matter streaming out of a black hole. And this black hole is 900 million light years away.
As reported at Popular Science, it required an array of 15 radio telescopes on Earth, and the Russian space telescope Spektr-R, to capture the image. This technique—called interferometry—is like creating a telescope that is 63,000 miles across. The detail it provides is like seeing a 50 cent coin on the Moon.
For perspective, the object in the image is 186 billion miles long, at minimum, and would just barely fit in the Oort Cloud.
The jet at the heart of BL Lacertae, with the Oort Cloud and Alpha Centauri for comparison. Image: Gomez et. al., A Lobanov, NRAO.
The Ariane5 lifting off from Kourou in French Guiana. Image: ESA/Arianespace.
The Ariane 5 rocket is a workhorse for delivering satellites and other payloads into orbit, but fitting the James Webb Space Telescope (JWST) inside one is pushing the boundaries of the Ariane 5’s capabilities, and advancing our design of space observatories at the same time.
The Ariane 5 is the most modern design in the ESA’s Ariane rocket series. It’s responsible for delivering things like Rosetta, the Herschel Space Observatory, and the Planck Observatory into space. The ESA is supplying an Ariane 5 to the JWST mission, and with the planned launch date for that mission less than three years away, it’s a good time to check in with the Ariane 5 and the JWST.
The Ariane 5 has a long track record of success, often carrying multiple satellites into orbit in a single launch. Here’s its most recent launch, on January 27th from the ESA’s spaceport in French Guiana. This is Ariane 5’s 70th successful launch in a row.
But launching satellites into orbit, though still an amazing achievement, is becoming old hat for rockets. 70 successful launches in a row tells us that. The Ariane 5 can even launch multiple satellites in one mission. But launching the James Webb will be Ariane’s biggest challenge.
The thing about satellites is, they’re actually getting smaller, in many cases. But the JWST is huge, at least in terms of dimensions. The mass of the JWST—6,500 kg (14,300 lb)—is just within the limits of the Ariane 5. The real trick was designing and building the JWST so that it could fit into the cylindrical space atop an Ariane 5, and then “unfold” into its final shape after separation from the rocket. This video shows how the JWST will deploy itself.
The JWST is like a big, weird looking beetle. Its gold-coated, segmented mirror system looks like multi-faceted insect eyes. Its tennis-court sized heat shield is like an insect’s shell. Or something. Cramming all those pieces, folded up, into the nose of the Ariane 5 rocket is a real challenge.
Because the JWST will live out its 10-year (hopefully) mission at L2, rather than in orbit around Earth, it requires this huge shield to protect itself from the sun. The instruments on the James Webb have to be kept cool in order to function properly. The only way to achieve this is to have its heat shield folded up inside the rocket for launch, then unfolded later. That’s a very tricky maneuver.
But there’s more.
The heart of the James Webb is its segmented mirror system. This group of 18 gold-coated, beryllium mirrors also has to be folded up to fit into the Ariane 5, and then unfolded once it’s separated from the rocket. This is a lot trickier than launching things like the Hubble, which was deployed from the space shuttle.
Something else makes all this folding and unfolding very tricky. The Hubble, which was James Webb’s predecessor, is in orbit around Earth. That means that astronauts on Shuttle missions have been able to repair and service the Hubble. But the James Webb will be way out there at L2, so it can’t be serviced in any way. We have one chance to get it right.
Right now, the James Webb is still under construction in the “Clean Room” at NASA’s Goddard Space Flight Centre. A precision robotic arm system is carefully mounting Webb’s 18 mirrors.
A robotic arm positions one of James Webb’s 18 mirrors. Image: NASA/Chris Gunn
There’s still over two years until the October 2018 launch date, and there’s a lot of testing and assembly work going on until then. We’ll be paying close attention not only to see if the launch goes as planned, but also to see if the James Webb—the weird looking beetle—can successfully complete its metamorphosis.
The first person to ever write an article for Universe Today (apart from me) was Tammy Plotner. Tammy was an experienced amateur astronomer, and had already dedicated her life to sharing her love of the night sky with the public. She spoke at astronomy clubs, did plenty of sidewalk astronomy, and in 2004, she contributed her first article to Universe Today.
By 2006, Tammy had written dozens of articles for Universe Today, and embarked on a weekly astronomy series called What’s Up This Week. We later turned those into actual books (printed on paper, no less), and did another edition in 2007.
One of my favorite projects that Tammy ever embarked on for Universe Today was to publish a guide to every single Messier Object, and every single Constellation in the sky. There are more than 100 Messier Objects, and 88 recognized constellations, and Tammy wrote an in-depth guide to each and every one.
To honor Tammy, we’ve decided to bring these wonderful guides back to the surface – you probably never even realized they were in the vast Universe Today archives. The Guide to Space Curator, Matt Williams, will be completely revised Tammy’s guides, adding plenty of new pictures and links to additional resources.
We’ll release one a week from both collections until they’re all republished, starting with M1: the Crab Nebula, today.
