$4.5 billion

Happy Asteroid Day, and happy Meteor Watch Day! Thousands of years ago, the world-famous Willamette meteorite, traveling some 64,000 kilometers per hour, crashed into Earth’s surface.

Billions of years before that, an early planet orbiting the Sun was shattered, perhaps in a collision with another protoplanet. While planets including Earth gradually formed and matured, the fragment orbited the Sun. Eventually, it landed in Oregon just outside of what is today the city of Portland. Over many centuries, rainwater interacting with its iron sulfide deposits produced sulfuric acid, which slowly etched and carved large cavities.

The Willamette is made of iron and weighs 15.5 tons.  It is the largest ever found in the United States and the sixth-largest in the world. Only about 600 of the 25,000 meteorites found on Earth are made of iron. The material was created deep inside stars, which produce energy by fusing lighter elements into heavier ones - for example, hydrogen into helium. The force of nuclear fusion eventually shatters stars much more massive than our Sun, casting fused elements, such as iron, into interstellar space. Over eons, these elements collect inside clouds of gas and dust. 

Within such an iron-rich interstellar cloud, our Sun formed 4.5 billion years ago, giving rise to comets, asteroids, planets and all life on Earth. So when we study the Willamette meteorite, we are also studying the chemical record of our origins and our place in the universe.

Whouffaldi’s (Twelve/Clara) romantic relationship is solid canon ... and confirmed by Moffat, Capaldi, and Coleman

I received an anonymous message asking me why I ship them so much because “he only thought of her as a friend – Clara doesn’t mean anything.”  I deleted it, but then I thought, Wait, I know that I’m right.  Whouffaldi fans know what we’ve seen onscreen, have multiple moments that confirm it.  So I did some digging.  And I found some interesting things online …:

* “Ultimately it has been confirmed by both Capaldi and Coleman that the Doctor and Clara’s relationship is romantic in nature … ”

* “Steven Moffat has teased that Capaldi’s Doctor may perhaps be more in love with Clara than he’d like to believe.”

* “ According to Coleman regarding Clara’s bond with The Doctor inquiring if she had feelings for him she stated ‘She’s totally in love with him ….’”

True love … DW style.  If Twelve could pick one person to see before he regenerates, it would be Clara.

Originally posted by dreameater1988

Originally posted by dreameater1988

I still ship them … and ship them proudly.  I won’t be dissuaded.  I ship them hardcore.

8

what a great day to celebrate sunshine~

i dont get why people try to convince me that the sun is 4.5 billion years old when he actually just turned 23??

#happyjhopeday

#happybirthdayhobi


*o.m // ɢɪᴈ & ᴘɪᴄᴛᴜʀᴇ ᴄʀ. ᴛᴏ ᴛʜᴇɪʀ ᴏᴡɴᴇʀᴤ*

On this day in 1969, with 600 million people watching on TV, an American crew landed on the Moon. The Apollo 11 mission had three crew members: Neil Armstrong, Buzz Aldrin, and Michael Collins. Collins piloted the craft that would return them to Earth, while the others became the first two people ever to walk the Moon’s surface.

Eventually, a total of six Apollo missions would land men on the Moon, the last arriving in December 1972. The missions brought the U.S. national glory– and more importantly, scientific results. Over the course of six moon landings, astronauts conducted invaluable geologic research. Using lunar sample collection bags, they eventually amassed more than 842 pounds (382 kilograms)[1] of Moon rocks, which are studied by lunar scientists to this day. These rocks were the key to demonstrating that the Moon formed from debris created when a Mars-sized object impacted Earth 4.5 billion years ago.

Photo: NASA

First 'image' of a dark matter web that connects galaxies

Researchers at the University of Waterloo have been able to capture the first composite image of a dark matter bridge that connects galaxies together. The scientists publish their work in a new paper in Monthly Notices of the Royal Astronomical Society.

The composite image, which combines a number of individual images, confirms predictions that galaxies across the universe are tied together through a cosmic web connected by dark matter that has until now remained unobservable.

Keep reading

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Twelve Days of Twelve - Day 3

Team TARDIS - Clara is my favorite companion for Twelve.  Her chemistry and bond with him was a joy to watch in Seasons 8 & 9.  He goes through hell, literally, mourning her death for 4.5 Billion Years because he loves her so much and he does anything to get her back.  He wrote a love song and called it “Clara” even though he couldn’t remember much about the woman that inspired it.  We know he recognizes her name, now, and that he remembers her face since he saw her in his memories.  Can’t wait to see them reunited!!!

4

NEW EVIDENCE THAT ALL STARS ARE BORN IN PAIRS

Did our Sun have a twin when it was born 4.5 billion years ago?

Almost certainly yes – though not an identical twin. And so did every other Sun-like star in the universe, according to a new analysis by a theoretical physicist from the University of California, Berkeley, and a radio astronomer from the Smithsonian Astrophysical Observatory at Harvard University.

Many stars have companions, including our nearest neighbor, Alpha Centauri, a triplet system. Astronomers have long sought an explanation. Are binary and triplet star systems born that way? Did one star capture another? Do binary stars sometimes split up and become single stars?

Astronomers have even searched for a companion to our Sun, a star dubbed Nemesis because it was supposed to have kicked an asteroid into Earth’s orbit that collided with our planet and exterminated the dinosaurs. It has never been found.

The new assertion is based on a radio survey of a giant molecular cloud filled with recently formed stars in the constellation Perseus, and a mathematical model that can explain the Perseus observations only if all Sun-like stars are born with a companion.

“We are saying, yes, there probably was a Nemesis, a long time ago,” said co-author Steven Stahler, a UC Berkeley research astronomer.

“We ran a series of statistical models to see if we could account for the relative populations of young single stars and binaries of all separations in the Perseus molecular cloud, and the only model that could reproduce the data was one in which all stars form initially as wide binaries. These systems then either shrink or break apart within a million years.”

In this study, “wide” means that the two stars are separated by more than 500 astronomical units, or AU, where one astronomical unit is the average distance between the Sun and Earth (93 million miles). A wide binary companion to our Sun would have been 17 times farther from the Sun than its most distant planet today, Neptune.

Based on this model, the Sun’s sibling most likely escaped and mixed with all the other stars in our region of the Milky Way galaxy, never to be seen again.

“The idea that many stars form with a companion has been suggested before, but the question is: how many?” said first author Sarah Sadavoy, a NASA Hubble fellow at the Smithsonian Astrophysical Observatory. “Based on our simple model, we say that nearly all stars form with a companion. The Perseus cloud is generally considered a typical low-mass star-forming region, but our model needs to be checked in other clouds.”

The idea that all stars are born in a litter has implications beyond star formation, including the very origins of galaxies, Stahler said.

Stahler and Sadavoy posted their findings in April on the arXiv server. Their paper has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.

Stars Birthed in ‘Dense Cores’

Astronomers have speculated about the origins of binary and multiple star systems for hundreds of years, and in recent years have created computer simulations of collapsing masses of gas to understand how they condense under gravity into stars. They have also simulated the interaction of many young stars recently freed from their gas clouds. Several years ago, one such computer simulation by Pavel Kroupa of the University of Bonn led him to conclude that all stars are born as binaries.

Yet direct evidence from observations has been scarce. As astronomers look at younger and younger stars, they find a greater proportion of binaries, but why is still a mystery.

“The key here is that no one looked before in a systematic way at the relation of real young stars to the clouds that spawn them,” Stahler said. “Our work is a step forward in understanding both how binaries form and also the role that binaries play in early stellar evolution. We now believe that most stars, which are quite similar to our own Sun, form as binaries. I think we have the strongest evidence to date for such an assertion.”

According to Stahler, astronomers have known for several decades that stars are born inside egg-shaped cocoons called dense cores, which are sprinkled throughout immense clouds of cold, molecular hydrogen that are the nurseries for young stars. Through an optical telescope, these clouds look like holes in the starry sky, because the dust accompanying the gas blocks light from both the stars forming inside and the stars behind. The clouds can, however, be probed by radio telescopes, since the cold dust grains in them emit at these radio wavelengths, and radio waves are not blocked by the dust.

The Perseus molecular cloud is one such stellar nursery, about 600 light-years from Earth and about 50 light-years long. Last year, a team of astronomers completed a survey that used the Very Large Array, a collection of radio dishes in New Mexico, to look at star formation inside the cloud. Called VANDAM, it was the first complete survey of all young stars in a molecular cloud, that is, stars less than about 4 million years old, including both single and multiple stars down to separations of about 15 astronomical units. This captured all multiple stars with a separation of more than about the radius of Uranus’ orbit – 19 AU – in our solar system.

Stahler heard about the survey after approaching Sadavoy, a member of the VANDAM team, and asking for her help in observing young stars inside dense cores. The VANDAM survey produced a census of all Class 0 stars – those less than about 500,000 years old – and Class I stars – those between about 500,000 and 1 million years old. Both types of stars are so young that they are not yet burning hydrogen to produce energy.

Sadavoy took the results from VANDAM and combined them with additional observations that reveal the egg-shaped cocoons around the young stars. These additional observations come from the Gould Belt Survey with SCUBA-2 on the James Clerk Maxwell Telescope in Hawaii. By combining these two data sets, Sadavoy was able to produce a robust census of the binary and single-star populations in Perseus, turning up 55 young stars in 24 multiple-star systems, all but five of them binary, and 45 single-star systems.

Using these data, Sadavoy and Stahler discovered that all of the widely separated binary systems – those with stars separated by more than 500 AU – were very young systems, containing two Class 0 stars. These systems also tended to be aligned with the long axis of the egg-shaped dense core. The slightly older Class I binary stars were closer together, many separated by about 200 AU, and showed no tendency to align along the egg’s axis.

“This has not been seen before or tested, and is super interesting,” Sadavoy said. “We don’t yet know quite what it means, but it isn’t random and must say something about the way wide binaries form.”

Egg-Shaped Cores Collapse into Two Centers

Stahler and Sadavoy mathematically modeled various scenarios to explain this distribution of stars, assuming typical formation, breakup and orbital shrinking times. They concluded that the only way to explain the observations is to assume that all stars of masses around that of the Sun start off as wide Class 0 binaries in egg-shaped dense cores, after which some 60 percent split up over time. The rest shrink to form tight binaries.

“As the egg contracts, the densest part of the egg will be toward the middle, and that forms two concentrations of density along the middle axis,” he said. “These centers of higher density at some point collapse in on themselves because of their self-gravity to form Class 0 stars.”

“Within our picture, single low-mass, Sun-like stars are not primordial,” Stahler added. “They are the result of the breakup of binaries. “

Their theory implies that each dense core, which typically comprises a few solar masses, converts twice as much material into stars as was previously thought.

Stahler said that he has been asking radio astronomers to compare dense cores with their embedded young stars for more than 20 years, in order to test theories of binary star formation. The new data and model are a start, he says, but more work needs to be done to understand the physics behind the rule.

Such studies may come along soon, because the capabilities of a now-upgraded VLA and the ALMA telescope in Chile, plus the SCUBA-2 survey in Hawaii, “are finally giving us the data and statistics we need. This is going to change our understanding of dense cores and the embedded stars within them,” Sadavoy said.


TOP IMAGE….Radio image of a very young binary star system, less than about 1 million years old, that formed within a dense core (oval outline) in the Perseus molecular cloud. All stars likely form as binaries within dense cores. (SCUBA-2 survey image by Sarah Sadavoy, CfA)

CENTRE IMAGE….A radio image of a triple star system forming within a dusty disk in the Perseus molecular cloud obtained by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. (Image: Bill Saxton, ALMA (ESO/NAOJ/NRAO), NRAO/AUI/NSF)

LOWER IMAGE….This infrared image from the Hubble Space Telescope contains a bright, fan-shaped object (lower right quadrant) thought to be a binary star that emits light pulses as the two stars interact. The primitive binary system is located in the IC 348 region of the Perseus molecular cloud and was included in the study by the Berkeley/Harvard team. (Image: NASA, ESA and J. Muzerolle, STScI)

BOTTOM IMAGE….A dark molecular cloud, Barnard 68, is filled with gas and dust that block the light from stars forming inside as well as stars and galaxies located behind it. These and other stellar nurseries, like the Perseus molecular cloud, can only be probed by radio waves. Credit: FORS Team, 8.2-meter VLT Antu, ESO

You know how Bill’s tear partially regenerated Twelve into waking up at the memories of all his friends… I think Steven always planned something like that because he never really wanted Twelve to forget Clara completely. 

Remember how we all said that if his memory hadn’t been wiped by Clara, he’d have been labelled PTSD-Doc for the Christmas special and series 10. But Steven was clever, he made it work. 

Clara wiped his memories. But he held on to her like a half-remembered tune in your head.. You hum it on occasion but you’ve no clue what the lyrics are. Then comes Christmas and he’s with River, 24 years. Then she goes and he’s sad again. But hey, there’s Nardie looking after him! Then he saves Missy and checks her into rehab. He meets Bill Potts and adopts her into his TARDIS crew. They go adventures. He gives Missy a chance and everything…

Twelve dies and Bill saves him with a tear filled with healing. He recalls the faces of every face he’s ever loved. Yes, ‘loved’ is the operative word. (And some of you ignored the fact he also remembered Missy. Yes, she is his arch enemy but she was his friend. Time Lords are weird like that.)

He wakes up and he’s regenerating, except he doesn’t want to.

Why doesn’t he want to regenerate?

I think the PTSD caught up. I think he remembers the 4.5 billion years. Clara. River. Missy. Bill.

I think he’s done with “dying” and coming back as another person. 

But where did these feelings come from?

I think we are going to get our answer in the Christmas special.

Did you know how sad William Hartnell was when he left Doctor Who

“I will not change. I will not.”

Then he sees himself approach him. And he half-remembers this moment. The moment when First met a man in the midst of snowstorm. 

We obviously don’t know details but I think Steven is bringing everything full circle. I think Steven is paying tribute to that through Twelve’s unwillingness to “die”. Hartnell was heartbroken and Steven is having Twelve mirror him, especially as he is properly heartbroken after everything he’s been through. 

I am so excited about the Christmas special. I am so excited.

Eight canonical facts about Clara Oswald

1. Clara Oswald gave the Doctor his inspiration and his mission statement, if you want to call it that, when she gave him encouragement as a child in Listen.

2. Clara Oswald scattered herself throughout the Doctor’s timestream in order to prevent the Great Intelligence from destroying everything he has ever done. This means every adventure prior to The Name of the Doctor has some manifestation of Clara nearby making sure all goes smoothly. This includes Silence in the Library/Forest of the Dead - the adventure in which the Doctor first met River Song. How we know this is because we see a Clara echo gazing upon the Tenth Doctor at the library. The only Doctor she did not meet, as far as we know, is the War Doctor - but Clara!Prime helped him directly.

3. The Moment failed to prevent the War, Tenth and Eleventh Doctor from activating her and destroying Gallifrey. Clara succeeded, absolving the Doctor of what was, by that time, centuries of guilt. (Oh, and she also saved the lives of 2.47 billion children on Gallifrey, by the way.)

4. Every Doctor from Twelve onwards, every single one will exist solely because of Clara Oswald convincing the Time Lords to give him a renewed regeneration cycle.

5. In a purely technical sense, Clara Oswald was the Doctor’s companion for 4.5 billion years. There is absolutely no other character in the series - other than the TARDIS (and yes, she’s a character) - to match that.

6. She is one half of the Hybrid, a pairing that terrifies even the Time Lords. (I’ve watched Hell Bent enough times that there is no ambiguity as to who the Hybrid is. When the Doctor says “I became the Hybrid,” he’s confirming Ashildr’s second theory that it’s him and Clara.)

7. She’s functionally immortal. (We don’t know yet if she can’t be killed a la Jack or Ashildr, but odds are that applies.)

8. She is the only companion to have her own personal TARDIS (I think Romana eventually got one in the Big Finish stories, but that’s not TV).


I’m just leaving this here because I get the feeling some Clara fans are feeling a little abandoned right now. As I’ve written a few times now, it doesn’t matter what happens in Series 10 or Christmas. These facts about Clara stand.

(An important PS: this post is not in any way a reaction to Bill. Just want to make that clear. I’m looking forward to seeing her story unfold.)

anonymous asked:

I just realised, tumblr thinks Jack and ashi is bad because Jack is like 70 but they had no problem with pearl and the mystery girl from Steven universe being a couple, and pearl is thousands of years old.

I’ve never seen SU, but yeah man, I can come up with a million similar ships that nobody bats an eye at. It seems that I’m an old veteran when it comes to shipping controversial ships with significant age differences lol. My all-time OTP for the past 3 years (The Twelfth Doctor and Clara Oswald (Doctor Who)), involves The Doctor who looks to be in his mid-fifties but is actually over 2,000 years old (technically over 4.5 billion years old now, actually), and Clara who looks to be in her mid-twenties, but she is actually physically 31 (and also technically billions of years old). Both characters are technically immortal and ageless, so the physical ages they appear to be are meaningless, but still the fandom went rabid lol, saying their relationship was disgusting, father-daughter, student-teacher, ect and then all getting proven wrong lol. Sounds familiar, huh?

However, unlike Jashi, they only became semi-canon, so there was no kiss, but holy hell there were so many other moments. I think I just live for ship tease lol, it’s half the fun of shipping to me. Analyzing everything, playing gifs over and over, listening to countless hints dropped by actors and screenwriters, theorizing…..ahhhgg I love it. This whole Jack and Ashi thing is basically one big deja vu for me lmao. I LIVE FOR IT

…..oh…and before yall fuss about het ships and stuff, Clara is canon bisexual and Twelve seems to be demi and pansexual, but he’s an alien so he doesn’t really conform to any of the categories 

Originally posted by dreameater1988

Originally posted by dreameater1988

Originally posted by rnarvel-ous

Originally posted by 324b213

Concerning Clara

So, if there’s one thing I’m really wanting right now it’s for Clara to reappear in the Christmas special. I’m pretty sure it would be the biggest missed opportunity ever if they failed to bring her back so Whouffaldi can be confirmed in a beautiful tribute to the characters.

Somehow meeting her again the neural block thing is broken and the Doctor can remember her. Cue flashback to the cloisters as we finally see their conversation, complete with a montage of their time together. Tears and hugs commence. The doctor is ready to regenerate and Clara’s time has come. One final confession is made, the same confession he made over 4.5 billion years trying to save her. The meaning of all those years, packed into three small words.

And with that closure they both go to their respective deaths, and we all cry forever.