Y Is For Ytterbium

Does the name “Pavlov” ring any bells?

The folks over at NASA just featured this nifty infographic on APOD about detecting objects in the sky:

How to Identify that Light in the Sky

What is that light in the sky?

Perhaps one of humanity’s more common questions, an answer may result from a few quick observations.

Image: HK (The League of Lost Causes)

For example — is it moving or blinking? If so, and if you live near a city, the answer is typically an airplane, since planes are so numerous and so few stars and satellites are bright enough to be seen over the din of artificial city lights.

If not, and if you live far from a city, that bright light is likely a planet such as Venus or Mars — the former of which is constrained to appear near the horizon just before dawn or after dusk.

Sometimes the low apparent motion of a distant airplane near the horizon makes it hard to tell from a bright planet, but even this can usually be discerned by the plane’s motion over a few minutes. Still unsure?

The above chart gives a sometimes-humorous but mostly-accurate assessment. Dedicated sky enthusiasts will likely note — and are encouraged to provide — polite corrections.

Why do we not discuss clouds more?

I mean look at that. That’s water.

Flying water.

FLYING

FUCKING

WATER

LIKE WHAT THE FUCK, WHY DO WE EVER STOP TALKING ABOUT THIS

WHAT IS THIS

HOW IS THIS EVEN

AND NOW THE FLYING WATER IS EATING A MOUNTAIN

GOD DAMN, WHAT

This image hurts my brain more than the original debate ever did. Brains are dumb.

For more posts like these, go to @mypsychology​

My kid is playing a paper piano. I think I might be more wowed than anyone else in my house.

Besides the nerdy factor of circuit completion and conductivity of graphite… It’s just kind of kickass that a paper piano that I drew can work just like a real one with minimal effort AND my kids can play it way easier than a real piano.

Magnetospheres: How Do They Work?

The sun, Earth, and many other planets are surrounded by giant magnetic bubbles.

Space may seem empty, but it’s actually a dynamic place, dominated by invisible forces, including those created by magnetic fields.  Magnetospheres – the areas around planets and stars dominated by their magnetic fields – are found throughout our solar system. They deflect high-energy, charged particles called cosmic rays that are mostly spewed out by the sun, but can also come from interstellar space. Along with atmospheres, they help protect the planets’ surfaces from this harmful radiation.

It’s possible that Earth’s protective magnetosphere was essential for the development of conditions friendly to life, so finding magnetospheres around other planets is a big step toward determining if they could support life.

But not all magnetospheres are created equal – even in our own backyard, not all planets in our solar system have a magnetic field, and the ones we have observed are all surprisingly different.

Earth’s magnetosphere is created by the constantly moving molten metal inside Earth. This invisible “force field” around our planet has an ice cream cone-like shape, with a rounded front and a long, trailing tail that faces away from the sun. The magnetosphere is shaped that way because of the constant pressure from the solar wind and magnetic fields on the sun-facing side.

Earth’s magnetosphere deflects most charged particles away from our planet – but some do become trapped in the magnetic field and create auroras when they rain down into the atmosphere.

We have several missions that study Earth’s magnetosphere – including the Magnetospheric Multiscale mission, Van Allen Probes, and Time History of Events and Macroscale Interactions during Substorms (also known as THEMIS) – along with a host of other satellites that study other aspects of the sun-Earth connection.

Mercury, with a substantial iron-rich core, has a magnetic field that is only about 1% as strong as Earth’s. It is thought that the planet’s magnetosphere is stifled by the intense solar wind, limiting its strength, although even without this effect, it still would not be as strong as Earth’s. The MESSENGER satellite orbited Mercury from 2011 to 2015, helping us understand our tiny terrestrial neighbor.

After the sun, Jupiter has by far the biggest magnetosphere in our solar system – it stretches about 12 million miles from east to west, almost 15 times the width of the sun. (Earth’s, on the other hand, could easily fit inside the sun.) Jupiter does not have a molten metal core like Earth; instead, its magnetic field is created by a core of compressed liquid metallic hydrogen.

One of Jupiter’s moons, Io, has intense volcanic activity that spews particles into Jupiter’s magnetosphere. These particles create intense radiation belts and the large auroras around Jupiter’s poles.

Ganymede, Jupiter’s largest moon, also has its own magnetic field and magnetosphere – making it the only moon with one. Its weak field, nestled in Jupiter’s enormous shell, scarcely ruffles the planet’s magnetic field.

Our Juno mission orbits inside the Jovian magnetosphere sending back observations so we can better understand this region. Previous observations have been received from Pioneers 10 and 11, Voyagers 1 and 2, Ulysses, Galileo and Cassini in their flybys and orbits around Jupiter.

Saturn’s moon Enceladus transforms the shape of its magnetosphere. Active geysers on the moon’s south pole eject oxygen and water molecules into the space around the planet. These particles, much like Io’s volcanic emissions at Jupiter, generate the auroras around the planet’s poles. Our Cassini mission studies Saturn’s magnetic field and auroras, as well as its moon Enceladus.

Uranus’ magnetosphere wasn’t discovered until 1986 when data from Voyager 2’s flyby revealed weak, variable radio emissions. Uranus’ magnetic field and rotation axis are out of alignment by 59 degrees, unlike Earth’s, whose magnetic field and rotation axis differ by only 11 degrees. On top of that, the magnetic field axis does not go through the center of the planet, so the strength of the magnetic field varies dramatically across the surface. This misalignment also means that Uranus’ magnetotail – the part of the magnetosphere that trails away from the sun – is twisted into a long corkscrew.

Neptune’s magnetosphere is also tilted from its rotation axis, but only by 47. Just like on Uranus, Neptune’s magnetic field strength varies across the planet. This also means that auroras can be seen away from the planet’s poles – not just at high latitudes, like on Earth, Jupiter and Saturn.

Does Every Planet Have a Magnetosphere?

Neither Venus nor Mars have global magnetic fields, although the interaction of the solar wind with their atmospheres does produce what scientists call an “induced magnetosphere.” Around these planets, the atmosphere deflects the solar wind particles, causing the solar wind’s magnetic field to wrap around the planet in a shape similar to Earth’s magnetosphere.

What About Beyond Our Solar System?

Outside of our solar system, auroras, which indicate the presence of a magnetosphere, have been spotted on brown dwarfs – objects that are bigger than planets but smaller than stars.

There’s also evidence to suggest that some giant exoplanets have magnetospheres. As scientists now believe that Earth’s protective magnetosphere was essential for the development of conditions friendly to life, finding magnetospheres around exoplanets is a big step in finding habitable worlds.  

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

I'm pretty new here, and I don't actually know much about dinosaurs (just followed this blog because it seemed really cool and interesting) so could you explain what shrink-wrapped means?

Of course! See, modern animals have a lot of muscles, fat, fluff, etc, and end up looking very little like their actual skeleton. For example, look at how much fluff owls have:

(Source)

However, lots of palaeoartists completely ignore this! They basically stretch skin over the bones and call it a day. One especially bad example that was featured on @palaeofail is this poor pterosaur:

It barely has room for its digestive system. It’s definitely missing the air sac system that allows it to breathe. It’s got virtually no muscles on the arms - how does it fly?? - on the head (no wonder its mouth is open. It has no jaw muscles to close it!), on the torso (it needs to flap), or on the legs (walking) It doesn’t have any fat at all, so it’s definitely starving (maybe because it can’t fly or close its moth?). The skin is much too thin; you can see all of the bones and its wing membranes should be much, much thicker. And it’s missing the hair-like pycnofibres that should be covering its body!

Many palaeoartists have started to strike back at this by drawing modern animals like we might draw them if we found their bones:

(Source)

[House cat]

(Source)

23 science facts we didn't know at the start of 2016

1. Gravitational waves are real. More than 100 years after Einstein first predicted them, researchers finally detected the elusive ripples in space time this year. We’ve now seen three gravitational wave events in total.

2. Sloths almost die every time they poop, and it looks agonising.

3. It’s possible to live for more than a year without a heart in your body.

4. It’s also possible to live a normal life without 90 percent of your brain.

5. There are strange, metallic sounds coming from the Mariana trench, the deepest point on Earth’s surface. Scientists currently think the noise is a new kind of baleen whale call.

6. A revolutionary new type of nuclear fusion machine being trialled in Germany really works, and could be the key to clean, unlimited energy.

7. There’s an Earth-like planet just 4.2 light-years away in the Alpha Centauri star system - and scientists are already planning a mission to visit it.

8. Earth has a second mini-moon orbiting it, known as a ‘quasi-satellite’. It’s called 2016 HO3.

9. There might be a ninth planet in our Solar System (no, Pluto doesn’t count).

10. The first written record demonstrating the laws of friction has been hiding inside Leonardo da Vinci’s “irrelevant scribbles” for the past 500 years.

11. Zika virus can be spread sexually, and it really does cause microcephaly in babies.

12. Crows have big ears, and they’re kinda terrifying.

13. The largest known prime number is 274,207,281– 1, which is a ridiculous 22 million digits in length. It’s 5 million digits longer than the second largest prime.

14. The North Pole is slowly moving towards London, due to the planet’s shifting water content.

15. Earth lost enough sea ice this year to cover the entire land mass of India.

16. Artificial intelligence can beat humans at Go.

17. Tardigrades are so indestructible because they have an in-built toolkit to protect their DNA from damage. These tiny creatures can survive being frozen for decades, can bounce back from total desiccation, and can even handle the harsh radiation of space.

18. There are two liquid states of water.

19. Pear-shaped atomic nuclei exist, and they make time travel seem pretty damn impossible.

20. Dinosaurs had glorious tail feathers, and they were floppy.

21. One third of the planet can no longer see the Milky Way from where they live.

22. There’s a giant, 1.5-billion-cubic-metre (54-billion-cubic-foot) field of precious helium gas in Tanzania.

23. The ‘impossible’ EM Drive is the propulsion system that just won’t quit. NASA says it really does seem to produce thrust - but they still have no idea how. We’ll save that mystery for 2017.