I Love This Kind Of News!

I love this kind of news!

“Voyager Spacecraft Fires Up Thrusters for First Time Since 1980”

NASA scientists have recently fired up the thrusters on the Voyager 1 Spacecraft - the farthest spacecraft from Earth - in an effort to reorient its antenna towards Earth. Originally, scientists would have used the attitude control thrusters aboard the spacecraft to make the adjustments, however these have been wearing out during the voyage. Instead, NASA scientists tried using Voyager’s ‘trajectory correction maneuver’ thrusters, located on the back side of the spacecraft. Since these hadn’t been fired in 27 years, engineers were thrilled when they received an answer 19 hours and 35 minutes later that the four thrusters had worked perfectly. "The Voyager team got more excited each time with each milestone in the thruster test. The mood was one of relief, joy and incredulity after witnessing these well-rested thrusters pick up the baton as if no time had passed at all,“ said Todd Barber, a propulsion engineer at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Read more about this fascinating story at: http://www.cnn.com/2017/12/01/us/voyager-1-thrusters-fired-first-time-since-1980/index.html

Image Credit: NASA, ESA, and G. Bacon (STScl)

Interesting facts about stars

Stars are giant, luminous spheres of plasma. There are billions of them — including our own sun — in the Milky Way Galaxy. And there are billions of galaxies in the universe. So far, we have learned that hundreds also have planets orbiting them.

1. Stars are made of the same stuff

All stars begin from clouds of cold molecular hydrogen that gravitationally collapse. As they cloud collapses, it fragments into many pieces that will go on to form individual stars. The material collects into a ball that continues to collapse under its own gravity until it can ignite nuclear fusion at its core. This initial gas was formed during the Big Bang, and is always about 74% hydrogen and 25% helium. Over time, stars convert some of their hydrogen into helium. That’s why our Sun’s ratio is more like 70% hydrogen and 29% helium. But all stars start out with ¾ hydrogen and ¼ helium, with other trace elements.

2. Most stars are red dwarfs

If you could collect all the stars together and put them in piles, the biggest pile, by far, would be the red dwarfs. These are stars with less than 50% the mass of the Sun. Red dwarfs can even be as small as 7.5% the mass of the Sun. Below that point, the star doesn’t have the gravitational pressure to raise the temperature inside its core to begin nuclear fusion. Those are called brown dwarfs, or failed stars. Red dwarfs burn with less than 1/10,000th the energy of the Sun, and can sip away at their fuel for 10 trillion years before running out of hydrogen.

3. Mass = temperature = color

The color of stars can range from red to white to blue. Red is the coolest color; that’s a star with less than 3,500 Kelvin. Stars like our Sun are yellowish white and average around 6,000 Kelvin. The hottest stars are blue, which corresponds to surface temperatures above 12,000 Kelvin. So the temperature and color of a star are connected. Mass defines the temperature of a star. The more mass you have, the larger the star’s core is going to be, and the more nuclear fusion can be done at its core. This means that more energy reaches the surface of the star and increases its temperature. There’s a tricky exception to this: red giants. A typical red giant star can have the mass of our Sun, and would have been a white star all of its life. But as it nears the end of its life it increases in luminosity by a factor of 1000, and so it seems abnormally bright. But a blue giant star is just big, massive and hot.

4. Most stars come in multiples

It might look like all the stars are out there, all by themselves, but many come in pairs. These are binary stars, where two stars orbit a common center of gravity. And there are other systems out there with 3, 4 and even more stars. Just think of the beautiful sunrises you’d experience waking up on a world with 4 stars around it.

5. The biggest stars would engulf Saturn

Speaking of red giants, or in this case, red supergiants, there are some monster stars out there that really make our Sun look small. A familiar red supergiant is the star Betelgeuse in the constellation Orion. It has about 20 times the mass of the Sun, but it’s 1,000 times larger. But that’s nothing. The largest known star is the monster UY Scuti. It is a current and leading candidate for being the largest known star by radius and is also one of the most luminous of its kind. It has an estimated radius of 1,708 solar radii (1.188×109 kilometres; 7.94 astronomical units); thus a volume nearly 5 billion times that of the Sun.

6. There are many, many stars

Quick, how many stars are there in the Milky Way. You might be surprised to know that there are 200-400 billion stars in our galaxy. Each one is a separate island in space, perhaps with planets, and some may even have life.

7. The Sun is the closest star

Okay, this one you should know, but it’s pretty amazing to think that our own Sun, located a mere 150 million km away is average example of all the stars in the Universe. Our own Sun is classified as a G2 yellow dwarf star in the main sequence phase of its life. The Sun has been happily converting hydrogen into helium at its core for 4.5 billion years, and will likely continue doing so for another 7+ billion years. When the Sun runs out of fuel, it will become a red giant, bloating up many times its current size. As it expands, the Sun will consume Mercury, Venus and probably even Earth.

8. The biggest stars die early

Small stars like red dwarfs can live for trillions of years. But hypergiant stars, die early, because they burn their fuel quickly and become supernovae. On average, they live only a few tens of millions of years or less.

9. Failed stars

Brown dwarfs are substellar objects that occupy the mass range between the heaviest gas giant planets and the lightest stars, of approximately 13 to 75–80 Jupiter masses (MJ). Below this range are the sub-brown dwarfs, and above it are the lightest red dwarfs (M9 V). Unlike the stars in the main-sequence, brown dwarfs are not massive enough to sustain nuclear fusion of ordinary hydrogen (1H) to helium in their cores.

10. Sirius: The Brightest Star in the Night Sky

Sirius is a star system and the brightest star in the Earth’s night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The system has the Bayer designation Alpha Canis Majoris (α CMa). What the naked eye perceives as a single star is a binary star system, consisting of a white main-sequence star of spectral type A0 or A1, termed Sirius A, and a faint white dwarf companion of spectral type DA2, called Sirius B.

To know more click the links: white dwarf, supernova, +stars, pulsars

sources: wikipedia and universetoday.com

image credits: NASA/JPL, Morgan Keenan, ESO, Philip Park / CC BY-SA 3.0

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matthewjopdyke

5 years ago

New Type Of Space Object Called “G Objects” Look Like Gas But Behave Like Stars! Found Near Our Supermassive Black Hole In The Milky Way.

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matthewjopdyke

6 years ago

This Is Why Hubble Can’t See The Very First Galaxies

This Is Why Hubble Can’t See The Very First Galaxies

“By observing dark, empty patches of sky, it reveals ancient galaxies without nearby interference. When distant galaxy clusters are present, these massive gravitational clumps behave as natural magnifying lenses. The most distant observed galaxies have their light bent, distorted, and amplified along the journey. Hubble discovered the current cosmic record-holder, GN-z11, via lensing. Its light arrives from 407 million years after the Big Bang: 3% of the Universe’s current age.”

No astronomical observatory has revolutionized our view of the Universe quite like NASA’s Hubble Space Telescope. With the various servicing missions and instrument upgrades that have taken place over its lifetime, Hubble has pushed back the cosmic frontier of the first stars and galaxies to limits never before known. Yet there must be galaxies before them; some of the most distant Hubble galaxies have stars in them that push back the time of the first galaxies to just 250 million years after the Big Bang. Yet Hubble is physically incapable of seeing that far. Three factors: cosmic redshift, warm temperatures, and light-blocking gas, prevent us from going much beyond what we’ve already seen. In fact, we’re remarkably lucky to have gotten as distant as we have.

Find out why Hubble can’t see the very first galaxies, and why we need the James Webb space telescope!

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matthewjopdyke

6 years ago

Further Than Before: Pathway to the Stars, Parts 1 and 2 - Update!

Further Than Before: Pathway to the Stars, Parts 1 and 2 – Update!

As with all authors of integrity, writing the message they truly have within them to share with the rest of the world, with the intent to entertain while edifying, rather than selling my ethics to whomever or whatever for the sake of big sales, I have made some updates to Parts 1 and 2 of the Further Than Before: Pathway to the Stars two-part series!

Whenever I find continuity issues, clarity…

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matthewjopdyke

10 years ago

No matter what people tell you, words and ideas can change the world.

http://www.brainyquote.com/quotes/authors/r/robin_williams.html

Black Holes are NICER Than You Think!

We’re learning more every day about black holes thanks to one of the instruments aboard the International Space Station! Our Neutron star Interior Composition Explorer (NICER) instrument is keeping an eye on some of the most mysterious cosmic phenomena.

We’re going to talk about some of the amazing new things NICER is showing us about black holes. But first, let’s talk about black holes — how do they work, and where do they come from? There are two important types of black holes we’ll talk about here: stellar and supermassive. Stellar mass black holes are three to dozens of times as massive as our Sun while supermassive black holes can be billions of times as massive!

Stellar black holes begin with a bang — literally! They are one of the possible objects left over after a large star dies in a supernova explosion. Scientists think there are as many as a billion stellar mass black holes in our Milky Way galaxy alone!

Supermassive black holes have remained rather mysterious in comparison. Data suggest that supermassive black holes could be created when multiple black holes merge and make a bigger one. Or that these black holes formed during the early stages of galaxy formation, born when massive clouds of gas collapsed billions of years ago. There is very strong evidence that a supermassive black hole lies at the center of all large galaxies, as in our Milky Way.

Imagine an object 10 times more massive than the Sun squeezed into a sphere approximately the diameter of New York City — or cramming a billion trillion people into a car! These two examples give a sense of how incredibly compact and dense black holes can be.

Because so much stuff is squished into such a relatively small volume, a black hole’s gravity is strong enough that nothing — not even light — can escape from it. But if light can’t escape a dark fate when it encounters a black hole, how can we “see” black holes?

Scientists can’t observe black holes directly, because light can’t escape to bring us information about what’s going on inside them. Instead, they detect the presence of black holes indirectly — by looking for their effects on the cosmic objects around them. We see stars orbiting something massive but invisible to our telescopes, or even disappearing entirely!

When a star approaches a black hole’s event horizon — the point of no return — it’s torn apart. A technical term for this is “spaghettification” — we’re not kidding! Cosmic objects that go through the process of spaghettification become vertically stretched and horizontally compressed into thin, long shapes like noodles.

Scientists can also look for accretion disks when searching for black holes. These disks are relatively flat sheets of gas and dust that surround a cosmic object such as a star or black hole. The material in the disk swirls around and around, until it falls into the black hole. And because of the friction created by the constant movement, the material becomes super hot and emits light, including X-rays.

At last — light! Different wavelengths of light coming from accretion disks are something we can see with our instruments. This reveals important information about black holes, even though we can’t see them directly.

So what has NICER helped us learn about black holes? One of the objects this instrument has studied during its time aboard the International Space Station is the ever-so-forgettably-named black hole GRS 1915+105, which lies nearly 36,000 light-years — or 200 million billion miles — away, in the direction of the constellation Aquila.

Scientists have found disk winds — fast streams of gas created by heat or pressure — near this black hole. Disk winds are pretty peculiar, and we still have a lot of questions about them. Where do they come from? And do they change the shape of the accretion disk?

It’s been difficult to answer these questions, but NICER is more sensitive than previous missions designed to return similar science data. Plus NICER often looks at GRS 1915+105 so it can see changes over time.

NICER’s observations of GRS 1915+105 have provided astronomers a prime example of disk wind patterns, allowing scientists to construct models that can help us better understand how accretion disks and their outflows around black holes work.

NICER has also collected data on a stellar mass black hole with another long name — MAXI J1535-571 (we can call it J1535 for short) — adding to information provided by NuSTAR, Chandra, and MAXI. Even though these are all X-ray detectors, their observations tell us something slightly different about J1535, complementing each other’s data!

This rapidly spinning black hole is part of a binary system, slurping material off its partner, a star. A thin halo of hot gas above the disk illuminates the accretion disk and causes it to glow in X-ray light, which reveals still more information about the shape, temperature, and even the chemical content of the disk. And it turns out that J1535’s disk may be warped!

Image courtesy of NRAO/AUI and Artist: John Kagaya (Hoshi No Techou)

This isn’t the first time we have seen evidence for a warped disk, but J1535’s disk can help us learn more about stellar black holes in binary systems, such as how they feed off their companions and how the accretion disks around black holes are structured.

NICER primarily studies neutron stars — it’s in the name! These are lighter-weight relatives of black holes that can be formed when stars explode. But NICER is also changing what we know about many types of X-ray sources. Thanks to NICER’s efforts, we are one step closer to a complete picture of black holes. And hey, that’s pretty nice!

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

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matthewjopdyke

6 years ago

A Much-Needed Skills, Contributions, and Direction

There are many times I ask myself, why didn’t I start a trade skill from the get-go? We can never underestimate how much it is that the people who are dedicated in these professions are a large part of that which brings a higher quality of life to all of us in one form or another. No matter what we do, if kindness and well-being are parts of our central or internal value system, humanity might…

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