In This Large Celestial Mosaic, Spitzer Space Telescope Captured A Stellar Family Portrait! You Can Find

On October 8 a privileged few could see auroras in abnormally low latitudes, as the spectacular pictures above taken in Wales and Northern England.

Via TON: Northern Lights Put On Spectacular Show As Aurora Borealis Lit Skies Over Wales And Yorkshire.

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How a blobfish looks with and without extreme water pressure. Blobfish live in water pressures 60-120 times greater than sea level.

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Strap in for a Tour of the Milky Way

The night sky isn’t flat. If you traveled deep into this part of the sky at the speed of the radio waves leaving this tower, here are some places you could reach.

Jupiter: Travel time – 35 minutes, 49 seconds.

The closest object in this view is the planet Jupiter, brilliant now in the evening sky…and gorgeous when seen up close by our Juno spacecraft. Distance on the night this picture was taken: 400 million miles (644 million kilometers). 

Saturn: Travel time – one hour and 15 minutes.

The next closest is Saturn, another bright “star” in this summer’s sky. On the right, one of the Cassini spacecraft’s last looks. Distance: 843 million miles (1.3 billion kilometers).

Pluto: Light-speed travel time from the radio tower – four hours, 33 minutes.

It’s not visible to the unaided eye, but Pluto is currently found roughly in this direction. Our New Horizons space mission was the first to show us what it looks like. Distance: more than 3 billion miles.

F-type star, HD 1698330: Light-speed travel time from the radio tower – 123 years.

Within this patch of sky, there’s an F-type star called HD 169830. At this speed, it would take you 123 years to get there. We now know it has at least two planets (one of which is imagined here) — just two of more than 4,000 we’ve found…so far.

The Lagoon Nebula: Light-speed travel time from the radio tower – 4,000 years.

If you look closely, you’ll see a fuzzy patch of light and color here. If you look *really* closely, as our Hubble Space Telescope did, you’ll see the Lagoon Nebula, churning with stellar winds from newborn stars.

Black hole, Sagittarius A*: Light-speed travel time from the radio tower – 26,000 years.

In 26,000 years, after passing millions of stars, you could reach the center of our galaxy. Hidden there behind clouds of dust is a massive black hole. It’s hidden, that is, unless you use our Chandra X-ray Observatory which captured the x-ray flare seen here.

The next time you’re under a deep, dark sky, don’t forget to look up…and wonder what else might be out there.

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

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The astro-fashion-loving Internet collectively gasped when ESA’s Hubble twitter account posted three gorgeous gowns, by Czech designer Jirina Tauchmanova with only credit “Photo: Vasek”, which google thinks is a Canadian tennis player. For four long days I couldn’t find anymore images, until, today! Which is why I’m sharing a belated #FashionFriday and #StarrySunday combo.

These gown were shown at Serbia Fashion Week back in December 2015 as Jirina Tauchmanova‘s Spring/Summer 2016 collection – I hope that means they will be available for purchase soon!

I think I recognize at least two of the images, NGC 602 & 30 Doradus, but I’m going to have to see these in person to be sure, yes, definitely, and probably try them on, too.

–Emily

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Behold NGC 6357, “cathedral to massive stars.” Credit: NASA, ESA and Jesús Maíz Apellániz (IAA, Spain). (NASA/APOD)

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Can you explain in a simple (???) way gravitational waves? please? do you know any books about it?

Sure!

According to Einstein’s General Theory of Relativity, what we think of as "empty space” isn’t nothing. Instead, space is more like a fabric that can be stretched, squashed, bent and shaped, and all matter and energy cause space to bend around them. The more mass or energy something has, the greater the bending of space around it it causes, a bit like heavier and lighter balls on a rubber sheet:

(Source - Note that this picture is a 2D analogy, and space is actually 3D! The bending of space isn’t something we can easily visualise, so we have to use analogies like the “balls on a rubber sheet” analogy - as long as we recognise their shortcomings!)

Let’s imagine the Sun is a bowling ball dropped onto a rubber sheet, creating a huge dent in space. And now let’s roll a marble - Earth - onto that sheet too. IF the marble is rolling too slowly, it will fall into the dent and roll around a few times, spiralling in and eventually colliding with the ball. If the marble is rolling too quickly, its path will be bent, but it will escape. If it’s rolling at a certain speed, however, the marble will roll around the bowling ball and go into orbit around it. (Here’s another shortcoming of the rubber sheet analogy - real rubber sheets have friction, so the marble would eventually slow down and roll in towards the bowling ball. Space, however, has no friction, so the Earth can stay in orbit around the Sun for a long time.) In other words, this bending of space is what we refer to as gravity!

In Newton’s view of gravity, Earth would naturally follow a straight line through space, but its path would be bent towards the Sun by a mysterious pulling force. That force holds the planets in orbit around the Sun and pulls apples to Earth, but Newton couldn’t explain why - a mysterious influence that spread out through space, called the gravitational field, somehow caused bodies to attract one another. Einstein explained that massive objects curve the space around them. Earth would also naturally follow a straight line through space, but the space itself is curved, forcing Earth to follow a curved path - it’s a bit like trying to walk in a straight line along a hill. Try as you might, your path will have to bend to follow the contours of the landscape. According to Einstein, gravity isn’t really a “force” as such but an effect of this bending of space. Matter and energy tell space how to bend; space tells matter and energy how to move. That’s all gravity is. The gravitational field isn’t some mysterious entity in space - the gravitational field is the space itself! Here’s a nice little video to help you visualise all this:

(I’m oversimplifying a little, btw, saying that gravity is the bending of “space.” In Einstein’s theory, the three dimensions of space are unified with time into one four-dimensional fabric, the space-time continuum. So gravity isn’t just the bending of space, but the warping of time too - you can’t change one without changing the other! Gravity actually slows time down, so you would age slightly faster in space than you do at Earth’s surface. The difference is incredibly tiny, but measurable - time passes more quickly for the GPS satellites than it does for us here on Earth, and what the clock of a GPS satellite would measure as “one day” is about 38 microseconds shorter than what we measure as “one day.” That doesn’t sound like a big difference, but engineers have to take it into account when designing GPS systems - if they didn’t account for this, your GPS location would drift by as much as 10 kilometres per day! So this isn’t just some abstract theory - this is a real effect that’s already important for technology you probably use every day.)

General Relativity has now been through many, many tests and has passed every one with flying colours, and all of its predictions had been verified by the beginning of 2016 except one - gravitational waves.

What would happen if we could somehow destroy the Sun? Newton believed that there was a mysterious gravitational connection between the Sun and Earth, holding Earth in its orbit, that would instantly be broken if the Sun was destroyed. Earth would instantly fly out of its orbit in a straight line. Einstein, however, didn’t like this - his Special Theory of Relativity (which he put out 10 years before the General Theory) says that no information could ever travel faster than light. It takes about 8 minutes for the Sun’s light to reach us, so how could Earth fly out of its orbit instantly? That would let us know the Sun had been destroyed 8 minutes before the light from the Sun’s destruction reached us. Einstein wasn’t comfortable with this.

Thankfully, General Relativity resolves the paradox - if you got rid of the Sun, Earth would still stay in its orbit for a while, because the space-time around the Sun would still be curved. Meanwhile, at the place where the Sun was, space-time would spring back to its original flat state, and that would ripple through the surrounding space-time as everything adjusted back to where it was. That ripple - a gravitational wave - would spread out through space at the speed of light, so the space around Earth would stay curved and Earth would remain in its orbit until the same time the light from the Sun’s destruction passed us - at which point the gravitational wave would ripple through the space around Earth and restore it back to its original flat state, and Earth would finally leave its orbit.

Of course, in reality, stars don’t just disappear. But the gravitational environment does change. Stars move around, and the fabric of space-time also moves with them. Stars explode. Black holes and neutron stars form, putting huge dents in space-time, and sometimes they collide. All these events are a bit like changing the environment in a still pond - stars and planets gently orbiting are like ducks gently gliding through the pond, creating gentle ripples as they disturb its surface - and black hole collisions are more like throwing a rock into the pond and sending out massive waves. Almost everything in our universe produces gravitational waves, but most of the time, they’re too tiny to detect. (That’s why I said in real space the Earth can orbit the Sun for “a long time,” and not “forever.” Earth is constantly sending out very faint gravitational waves as it rolls around the Sun and moves through the fabric of space-time. Those waves are too small to detect, but they very, very slowly sap Earth’s energy and cause it to very, very slowly spiral in to the Sun. In reality, that would take unimaginable trillions upon trillions of years, and Earth will probably be destroyed by the dying Sun long before that! Even if Earth manages to survive that, it’s more likely to be pulled out of orbit by an incredibly rare passing star or knocked out by unpredictable gravitational tugs from the other planets or something before it spirals into the Sun. Orbits are stable for a very, very, very, very long time.) More intense sources of gravity than our puny Earth and Sun, however - things like neutron stars and black holes - can generate detectable gravitational waves.

Our first indirect evidence of gravitational waves came in 1984, when the American astronomers Russel A. Hulse and Joseph A. Taylor discovered a binary neutron star system - two intense sources of gravity orbiting each other very rapidly. As they orbited each other, they sent out huge gravitational ripples - a bit like stirring up that duck pond with two oars whirling round and round - and lost energy by a detectable amount. Hulse and Taylor found that their orbital period slowed down by about 75 milliseconds per year - short, but detectable! That slowing exactly matched the predictions of gravitational wave theory and got its discoverers the Nobel Prize for Physics in 1993.

(Source)

But gravitational waves weren’t directly observed until 2015 (and confirmed until this year) by a detector named LIGO (the Laser Interferometer Gravitational wave Observatory). All LIGO is is basically two beams of laser light travelling between two pairs of mirrors oriented at right angles to each other, like this, so you can measure how space-time is stretched in one direction and squashed in the other by a passing gravitational wave by recording how long it takes the light to travel from one mirror to the other*:

(Source for both images: http://phys.org/news/2016-02-ligo.html)

LIGO’s two “arms” (the two beams of light) are each 4 kilometres long, and a gravitational wave passing through the detector stretches or squashes each of the “arms” by a ridiculously small amount - the ones LIGO actually found stretched and about 1/10,000th the width of a proton. As you can imagine, the LIGO physicists had to account for many, many different effects that shook the detector too. But gravitational waves distort the two beams in a predictable way that would make that distortion stand out from ordinary passing trucks or distant earthquakes, and by February 11th, 2016, the LIGO physicists were confident enough that they really had detected a faint ripple in space-time passing through their detector. The signal was consistent with a gravitational wave from two black holes in orbit around each other, spiralling in to one another.

(Source)

This is exciting for two reasons:1) It confirms the last outstanding prediction of General Relativity, and2) It opens up a whole new field of astronomy! Every so often astronomy is revolutionised by the discovery of new things we can look at from space. Originally all we could detect was the visible light that we could see with our eyes and telescopes. But soon we learned to build radio telescopes, and that opened up a whole new world to us - we could see phenomena that were invisible in ordinary light. With space telescopes we could see the sky in gamma rays, x-rays, ultraviolet and infra-red light as well. Now we could see the explosions of distant stars halfway across the observable Universe, look at clouds of gas and dust too cool to shine in visible light, and peer through other dark clouds to see stars forming inside. We also found particles we could see coming from space, too - neutrinos from the Sun and from supernovae, and cosmic rays. These opened up other windows on the Universe. And now we have gravitational waves - yet another new way of “seeing.” Gravitational wave astronomy will let us study some of the most puzzling events in the Universe, like colliding neutron stars, or black holes falling into other black holes - events we’ve never been able to see before. 

So I hope that helps, Anon! 

As for books, the problem is gravitational waves were detected so recently I don’t know of any books that have come out since then on the subject, so everything will be out of date. However, the basic physics has stayed the same since Einstein first predicted them, so any good popular book on general relativity (Spacewarps by John Gribbin, The Fabric of the Cosmos by Brian Greene and Travelling At the Speed of Thought: Einstein and the Quest for Gravitational Waves by Daniel Kennefick are good examples) should give you some good insight - just replace phrases like “if we detect gravitational waves” with “when we detected gravitational waves!”

(*Yes, yes, I know LIGO isn’t actually measuring the time taken for light to travel down each “arm,” but the interference of the laser beams. Still, that interference allows us to infer the travel time for the light, so I’m simplifying.)

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SwRI’s Parker discovers moon over Makemake in the Kuiper Belt A Southwest Research Institute-led team has discovered an elusive, dark moon orbiting Makemake, one of the “big four” dwarf planets populating the Kuiper Belt region at the edge of our solar system. The findings are detailed in the paper “Discovery of a Makemakean Moon,” published in the June 27 issue of Astrophysical Journal Letters.

“Makemake’s moon proves that there are still wild things waiting to be discovered, even in places people have already looked,” said Dr. Alex Parker, lead author of the paper and the SwRI astronomer credited with discovering the satellite. Parker spotted a faint point of light close to the dwarf planet using data from Hubble’s Wide Field Camera 3. “Makemake’s moon – nicknamed MK2 – is very dark, 1,300 times fainter than the dwarf planet.”

A nearly edge-on orbital configuration helped it evade detection, placing it deep within the glare of the icy dwarf during a substantial fraction of its orbit. Makemake is one of the largest and brightest known Kuiper Belt Objects (KBOs), second only to Pluto. The moon is likely less than 100 miles wide while its parent dwarf planet is about 870 miles across. Discovered in 2005, Makemake is shaped like football and sheathed in frozen methane.

“With a moon, we can calculate Makemake’s mass and density,” Parker said. “We can contrast the orbits and properties of the parent dwarf and its moon, to understand the origin and history of the system. We can compare Makemake and its moon to other systems, and broaden our understanding of the processes that shaped the evolution of our solar system.”

With the discovery of MK2, all four of the currently designated dwarf planets are known to host one or more satellites. The fact that Makemake’s satellite went unseen despite previous searches suggests that other large KBOs may host hidden moons.

Prior to this discovery, the lack of a satellite for Makemake suggested that it had escaped a past giant impact. Now, scientists will be looking at its density to determine if it was formed by a giant collision or if it was grabbed by the parent dwarf’s gravity. The apparent ubiquity of moons orbiting KBO dwarf planets supports the idea that giant collisions are a near-universal fixture in the histories of these distant worlds.

top Image: illustration shows Makemake’s bright red surface and the inferred darker surface of the moon, known as MK2. Image Courtesy of NASA/SwRI/Alex Parker

lower Image: Different views of the Makemake system taken two days apart. Image Courtesy of NASA/Hubble WFC3/SwRI/Alex Parker

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i get a LOT of questions about time management and getting better grades so i decided to put a boat load of advice and links in one place :]

time management methods

start a bullet journal ( +mine / +insp )

the 5 day study plan - it works!

schedule blocks of study time

use excel to schedule study

how to schedule study

the sticky note method

an app that organizes time for u

15 ways to beat procrastination

balancing multiple AP classes

decision making and time management

use the pomodoro technique

the task box prioritizing method

how to cram a lot of information in

get organized!!!!!

make and use a syllabible

great organization advice

organize ur study space

more tips on study spaces

basic organization tips

cute infographic

printable planner sheets

simple 2 pocket folder method

study methods!!!

watch youtube crashcourses

best study tips ever tbh

tips on memorizing effectively

add color for visual interest

make cause and effect diagrams

making good flashcards

create summary foldables

margin note taking

the 2 notebook method

for when ur not motivated

reading long textbook passages

studying for a test ooh

basic note taking

+note taking tips

note taking in microsoft word

bs study guide

how to plan out an essay

more essay planning

annotating literature for english

how to make concept maps

really interesting way of studying

shit load of study methods

web resources!!!!

search engine that plants trees!

to do list web program

bedtime calculator [avoid grogginess]

the dictionaries u need omg

how to pull an all nighter

advice on how to properly use google

final grade calculator

>100 places to download literature

cute af school supply list

alternatives to overpriced textbooks

rly this is better than google

best writing checker ever its my fave

free academic journals for research

AP cramming packets

every website to make a bibliography

online used book store

mind map making software from tufts

khanacademy aka bless this site

stop procrastinating websites

free powerpoint

awesome synonym finder

apps u need to download!!!

google chrome app i love it

taking digital notes

like 14 useful school apps

attn: all writers get this

super cute time manager

>9 different studying apps

post it note app

study + give water to needy!!

relaxation n meditation help

sat help!!!!!

all kinds of essential vocab [2k+]

big collection of links

v solid page with lots of references

rly good advice imo

how to do well on the sat

general big exam advices

stress reliefs!!!!

rly good study snacks

badass instrumental playlist!

finish ur essay songs!

+all my fave study playlists!

treat urself on a low budget

read some rad articles

teach urself computer science

take the 10 day study challenge

rip some crap online

good things to do in study breaks

+100 more things in study breaks

if u tired and uninspired

avoid student burnout

watch a ton of broadway musicals

nice things for urself

anxiety relieving background sound

+masterposts!!!

back to school advice

productive summers

note taking methods

starting a study blog

time managements

succeed @ school

ap world history

study instagram

web resources

ap psychology

bullet journals

school advice

happy things

ace ur exams

study sounds

stress reliefs

annotations

essay writin

study 101

printables

sat help

+more

i hope some of this was helpful ~ i also have a youtube channel and instagram account with a whole bunch of study resources!!!!  ~ xoxo sareena

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