Astronomy Rewind: January 2019

Dark Matter Heating, White Dwarfs, NASA Mission Updates and More…

Poster designed by Pavan Bhushan

Aptly named after the God of beginnings, January has been a diligent month. There was no scarcity of the discoveries we humans have made and it doesn’t seem to slow down any time soon.

With the month coming to an end, here we bring you our insights of the best-curated updates from the last 31 days, all at one place.

Top Stories of the Month

  • Understanding Titan (Nope, not Thanos’s homeworld)
Image of Titan

Earth is the only planet known to have a Nitrogen-rich atmosphere but we are not alone. Turns out that Titan, Saturn’s largest moon also does, making up to 97% of its atmosphere. Just like how the Earth has lakes of water, Titan has lakes of liquid methane. If that doesn’t impress you, how about methane rainfall? With that being said, Titan is easily one of the most interesting moons astronomers yearn to explore.

By observing a short-lived shiny surface, scientists theorize that it is likely a reflection of sunlight by a wet surface. We have previously observed summer in the southern hemisphere and this is the first evidence of it in the northern hemisphere. This indicates that Titan has its own seasonal cycle.

Titan is sure to host a myriad of interesting organic reactions and we now have good insights to plan out future mission objectives when we visit this place again.

  • The Mystery Behind the Stellar “Cow”

Looking at the above images, what do you infer? Something extraordinarily peculiar happened. A bright patch appeared out of nowhere, more luminous than its host galaxy. This sent scientists wondering what in this universe could have caused such a huge glow? In the days that followed this detection, several theories were put forth to explain it but the exact reason for this phenomenon still remains inconclusive. Scientists call this event “the Cow” taken from an autogenerated name.

A day before, there was hardly anything abnormal in that region of the sky and the very next day scientists observed luminosity of 100 billion suns, much larger than a normal supernova and it unusually remained so for a while.

One theory suggested that it could have been a supernova that created a black hole or a neutron star at its core, while another one proposed that it may have caused due to the shredding of a white dwarf as it approached an intermediate black hole. This theory seemed to have some shortcomings though.

Whatever caused this explosion is sure to be one among the most violent events out there. More observations are being made of this region and soon we might find a better explanation.

Talking about White Dwarfs, astronomers have made some interesting observations recently.

  • The Fate of the White Dwarfs
White dwarf star in the process of solidifying. Credit: University of Warwick/Mark Garlick

Somethings stay the same for eternity but stars are definitely not one of them even though they seem to be. In about 10 billion years from now, a star like our sun would have become a white dwarf.

If you ever wondered how solid oxygen would look like, the core of a white dwarf is where you can find it. For the first time, scientists observed evidence that points out to a special phase in the life cycle of a white dwarf, crystallization (conversion of a liquid into a solid). It was observed that the Oxygen and Carbon in the star solidify due to immense pressure and settle in the core. It is estimated that all white dwarfs must go through this phase at some point in their life cycle. The discovery of this phase helps us in gauging the age of these stars more accurately.

  • Evidence of Dark Matter Heating
Image Credits: Live Science

Most astronomical observations point to something strangely missing from our view. There has to be something elusive out there for our universe to be the way we observe it, and it has to make up about 85% of all matter! Scientists call it dark matter. It’s dark and mysterious (but well, it’s definitely not from the DC universe) and we know so little about it. We often measure the gravitational effects to determine the presence and density of this type of matter.

Today we know a little bit more about the nature and properties of this matter. Scientists found evidence of dark matter being heated due to star formation in dwarf galaxies. By heating, we imply that it is gaining energy. It was found that older galaxies that had no star formation had higher densities of dark matter at their centre compared to the younger ones with active star formation.

These observations suggest that dark matter is possibly gaining energy due to which it is moving away from the centre. One direct conclusion from this study is that the density of dark matter in a dwarf galaxy is related to the rate of star formation.

There is still a long way to go in understanding the exact nature of dark matter but we are surely a step closer now.

  • The First Plants on Moon
Cotton plants have been seen budding and growing, as shown by this close-up of the plants sprouting under a protective cover on the Chang’e 4 lunar lander.

Moon is pretty hostile to any kind of plant or animal life but still, our curiosity pushed us to grow plants on the lunar surface. The cotton seeds that was on board the Chinese Chag’e 4 Probe germinated! The probe hosted several other life forms in a sort of a sealed mini biosphere including fruitfly eggs and yeast. The plants soon died due to drastic fluctuations of temperature on the moon which is quite difficult to maintain.

But well, we started the year being able to say, “Look up! life isn’t just unique to Earth anymore”, even if it was for a brief period.

  • Total Lunar Eclipse

Talking about the Moon, how can we not discuss the lunar eclipse that happened this month!

The eclipse as seen from Oria, Italy, at 5:43 UTC, January 21, at the end of totality

Also referred to as the ‘Super Blood Wolf Moon’, it coincided with Moon’s closest approach to Earth. We were all prepared for the eclipse but the meteor impact came out of syllabus. It crashed into the lunar surface right during the eclipse. For the first time, such a unique event was captured on video.

You will have to wait till 2021 to witness the next total lunar eclipse, but there are some partial eclipses around the year to satiate your lunar shenanigans.

Space Mission Highlights

Here are some of the hottest updates of the month from various space probes currently in action.

  • TESS’s First Results (Transiting Exoplanet Survey Satellite)

For hundreds of years, mankind has just known about the solar system and its eight planets. Ancient astronomers had a tough time spotting most of them but for TESS however, finding exoplanets is almost like an everyday routine.

Launched last year, TESS has already discovered hundreds of potential candidates and as of January 2019, eight of them have been confirmed. That’s a promising start for the mission. To explore more about the discoveries made by TESS so far, check out this article:

  • Juno’s Jupiter Flyby

NASA’s Juno made another pass over Jupiter’s surface late last month. It captured a stunning view of two enormous storms swirling across the gas giant. Along with the famous Great Red Spot storm is a second storm nicknamed Oval BA that was formed when three smaller storms collided in 2000.

Jupiter’s icy moon Europa provides another opportunity for exploration. ‘Europa Clipper’ as named by NASA is a planned mission that will investigate the habitability of this Jupiter’s moon. An extensive ocean is thought to exist below the icy surface. Since the Hubble Space Telescope has detected plumes erupting from this ocean multiple times in recent years, it increases the chances of life on Europa. Europa Clipper would be designed to fly past the moon for about 40 to 45 times to help scientists learn more about Europa’s environment: its icy surface, interior and the heavy amounts of radiation surrounding it, coming from Jupiter.

  • Parker Solar Probe Into Its Second Trip Around The Sun
Artist Impression of Parker (Image Credits: NASA)

NASA’s Parker Solar Probe aces its 1st trip around our Star and entered the second of the 24 planned orbits. Parker was designed to take care of itself and its precious payload during its close approach to the Sun, with no control from the team on Earth, and it was successful.

The spacecraft will continually break its own speed record as its orbit draws closer to the star and the spacecraft travels faster and faster.

According to the NASA officials, the spacecraft has already delivered 17 gigabits of science data from its first orbit and would transmit its full observations from the orbit by April.

Its four instrument suites will help scientists begin to answer outstanding questions about the Sun’s fundamental physics — many of which have befuddled us for long like how the particles and solar material are accelerated out into space at such tremendous velocities and why the Sun’s atmosphere, the corona, is so much hotter than the surface below.

  • New Horizons Successfully Explores Ultima Thule
The farthest object explored by humans to this date. (Image Credits: NASA)

Standing true to its name, New Horizons made history on New Year’s Eve exploring Ultima Thule located beyond the final frontiers that humans have ever reached. Only days later did we get the data collected, that much was the distance between Earth and where the probe is right now.

Like a snowman in space, it stays silent and surprisingly soft indicating that the Kuiper belt wasn’t as violent in the past as estimated. Ultima appears to be similar to a comet nucleus further strengthening the theory of the origin of comets.

New Horizons will continue to transmit data until as long as September 2020 which will help us better understand this pristine structure of our solar system and other Kuiper belt objects.

  • Curiosity Continues Its Journey on Mars
A selfie taken by NASA’s Curiosity Mars rover on Sol 2291 (January 15) at the “Rock Hall” drill site, located on Vera Rubin Ridge. Credits: NASA/JPL-Caltech/MSSS

Ever since NASA’s Curiosity rover landed on the 96 miles wide (154 km) Gale Crater in 2012, it has exceeded all our expectations in exploring and mapping the surface of Mars. One of its primary objectives was to explore the area’s past potential to host life. A martian mountain (named Aeolis Mons) that rises as high as 5 km into the Martian sky from the centre of the crater is a dramatic geological oddity that has no close parallel here on Earth. This makes the crater more intriguing.

“Mission team members repurposed the rover’s navigation gear to measure tiny variations in gravitational fields, a new study reports.”

This novel approach allows the researchers to know how the Martian mountain was formed.

Curiosity is now headed into the “clay-bearing unit,” which sits in a trough just south of the ridge it has been exploring so far. Clay minerals in this unit may hold more clues about the ancient lakes that helped form the lower levels on Aeolis Mons.

A Picture Worth a Million Stars

Let us conclude this edition with our pick for the image of the month. Beautiful is an understatement to describe this gem of a picture taken by the Hubble Space Telescope.

This is the Triangulum galaxy, one of our cosmic neighbours. What you are looking at right now are 25 million stars, countless nebulae, and dust clouds, all resolved within a 660 million pixelated picture, making it the second sharpest image to this date. (Guess, what's the sharpest image then?)

The Triangulum Galaxy. Photo: NASA, ESA, and M. Durbin, J. Dalcanton, and B.F. Williams

You can view this humongous picture in all its glory and actual pixel size by visiting this link and using the interactive zoom tool:

Bonus Image

Well, how can we not include the SpaceX’s Starship? Elon Musk has shared this breathtaking picture on his twitter handle earlier this month and we cannot get enough of it.

The Starship that will someday take humans to Mars

Stay tuned for the next edition of Astronomy Rewind and do follow Nakshatra to join us in our exploration of the cosmos.

#StayCurious

“Absence of evidence is not evidence of absence” — Carl Sagan

This article was co-authored by Shivaranjani Shankar of Nakshatra.

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