The Tarantula Nebula (also Known As 30 Doradus) As Seen From The Hubble Space Telescope.

Catching prey using Vortices

I was reading about Vortices and after hours of research online, out of the blue I stumbled upon this amazing bird. This is the Red Necked Phalarope and from the looks of it seems to have put vortices to a really productive use - catching its prey.

By rotating around ~60-80 times a minute, it produces an upward vortex that sucks out insects/bugs/crustaceans from the water, which it swiftly picks up with its beak and eats. ( This one would have aced the Fluids class for sure :D)

This is analogous to tornadoes sweeping up cars and houses along its way in an upward swirl.

Mind Blown!

** The actual dynamics of vortices of course is waay more complicated. ;)

*** There are three species of phalarope (red-necked, red/grey, and Wilson’s), and they can all feed like that.            

In this detailed view from NASA’s Hubble Space Telescope, the so-called Cat’s Eye Nebula looks like the penetrating eye of the disembodied sorcerer Sauron from the film adaptation of “The Lord of the Rings.”

The nebula, formally cataloged NGC 6543, is every bit as inscrutable as the J.R.R. Tolkien phantom character. Though the Cat’s Eye Nebula was one of the first planetary nebulae to be discovered, it is one of the most complex such nebulae seen in space. A planetary nebula forms when Sun-like stars gently eject their outer gaseous layers that form bright nebulae with amazing and confounding shapes.

In 1994, Hubble first revealed NGC 6543’s surprisingly intricate structures, including concentric gas shells, jets of high-speed gas, and unusual shock-induced knots of gas.

As if the Cat’s Eye itself isn’t spectacular enough, this new image taken with Hubble’s Advanced Camera for Surveys (ACS) reveals the full beauty of a bull’s eye pattern of eleven or even more concentric rings, or shells, around the Cat’s Eye. Each ‘ring’ is actually the edge of a spherical bubble seen projected onto the sky — that’s why it appears bright along its outer edge.

Observations suggest the star ejected its mass in a series of pulses at 1,500-year intervals. These convulsions created dust shells, each of which contain as much mass as all of the planets in our solar system combined (still only one percent of the Sun’s mass). These concentric shells make a layered, onion-skin structure around the dying star. The view from Hubble is like seeing an onion cut in half, where each skin layer is discernible.

Until recently, it was thought that such shells around planetary nebulae were a rare phenomenon. However, Romano Corradi (Isaac Newton Group of Telescopes, Spain) and collaborators, in a paper published in the European journal Astronomy and Astrophysics in April 2004, have instead shown that the formation of these rings is likely to be the rule rather than the exception.

The bull’s-eye patterns seen around planetary nebulae come as a surprise to astronomers because they had no expectation that episodes of mass loss at the end of stellar lives would repeat every 1,500 years. Several explanations have been proposed, including cycles of magnetic activity somewhat similar to our own Sun’s sunspot cycle, the action of companion stars orbiting around the dying star, and stellar pulsations. Another school of thought is that the material is ejected smoothly from the star, and the rings are created later on due to formation of waves in the outflowing material. It will take further observations and more theoretical studies to decide between these and other possible explanations.

Approximately 1,000 years ago the pattern of mass loss suddenly changed, and the Cat’s Eye Nebula started forming inside the dusty shells. It has been expanding ever since, as discernible in comparing Hubble images taken in 1994, 1997, 2000, and 2002. The puzzle is what caused this dramatic change? Many aspects of the process that leads a star to lose its gaseous envelope are still poorly known, and the study of planetary nebulae is one of the few ways to recover information about these last few thousand years in the life of a Sun-like star.

Object Names: Cat’s Eye Nebula, NGC 6543

Image Type: Astronomical

Credit: NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA)

Acknowledgment: R. Corradi (Isaac Newton Group of Telescopes, Spain) and Z. Tsvetanov (NASA)

Time And Space

For The First Time, Scientists Have Measured The Mysterious Force That Makes Crystals Align

Crystals have a force of their own.

Crystals are among the most fascinating structures in the natural world - not only do they have a unique, highly ordered, and repeating lattice structure, they also have all kinds of inherent, interesting properties, including the ability to self-assemble.

When placed next to each other, tiny crystals will twist, snap into alignment, and slam into each other to form larger crystals, and for the first time, scientists have visualised and measured the force that makes this possible.

By using a new visualisation technique, the team showed that the force that governs crystals is a type of van der Waals force, a quantum attraction that’s not reliant on any chemical bonds (such as the covalent bonds that hold molecules together).

It’s the same type of force that allows geckos’ feet to stick to walls and ceilings - and now scientists have shown that it also works to twist and fuse crystals together, allowing them to get larger and larger.

Continue Reading.

Ask Ethan: Can The Universe Still End In A Big Crunch?

“You [wrote] that the Universe is expanding at a decreasing rate. I thought a Nobel Prize was awarded for the “discovery” that the Universe was expanding at an increasing rate. Can you please clarify the leading theories? Is the “Big Crunch” still a possibility?”

Have you heard about the accelerating Universe? What about dark energy, vacuum energy, or a cosmological constant? These are terms we throw around to talk about one of the strangest observations ever made in the Universe: that the more distant a galaxy is from us, the faster it appears to be receding from us. Not only that, but the rate of recession appears to actually increase over time, which is the biggest puzzle of all. But what does this mean for the expansion rate of the Universe? While you might think, as many do, that this means the expansion rate itself is accelerating, that’s not how it works at all. The expansion rate is dropping today, and will continue to drop, eventually asymptoting to a constant value. So how does this cause acceleration, and what does that mean for the fate of the Universe?

Find out on this week’s Ask Ethan, and learn how a Big Crunch and a Big Rip are not only still possibilities, but how we’re going to attempt to find out whether either one might be real!

What if cosmic inflation is wrong?

“One side goes so far as to claim that because you can contrive models that can give you almost arbitrary behavior, inflation fails to rise to the standard of a scientific theory. The other side claims that inflation makes these generic, successful predictions, and that the better we measure these parameters of the Universe, the more we constrain which models are viable, and the closer we come to understanding which one(s) best describe our physical reality.”

The Big Bang is commonly regarded as the start of it all, but that’s only the birth of what we call our observable Universe. There must have been something compelling to set it up, complete with the initial conditions that our Universe began with. An idea called Cosmic Inflation fits the bill perfectly, providing those conditions and making six explicitly new predictions. Despite the fact that five of them have been observationally verified, there are still detractors of inflation, who go as far as to proclaim that inflation isn’t even a scientific theory. It’s not a crazy claim, but it’s not entirely fair, either.

Come find out what the controversy is all about, and learn what it means if cosmic inflation is wrong!

Filter by Wadim Kashin

You can explore the solar system—and maybe even help scientists discover a new planet—thanks to Backyard Worlds: Planet 9, a new citizen-science tool developed by NASA in collaboration with the American Museum of Natural History and other partners and released today.

“It’s hard to believe, but our solar neighborhood is still unexplored territory,” said Jackie Faherty, a senior scientist in the Museum’s Department of Astrophysics and a collaborator on the project. “There are cold worlds hiding just a short distance from the Sun, and Backyard Worlds: Planet 9 is a platform for bringing citizen scientists into the search party.”

Read more about the project on our blog.

Happy Birthday Yuri Gagarin! On this day in 1934, cosmonaut Yuri Gagarin was born. 27 years later, Gagarin flew aboard Vostok 1 – and in doing so, became the first ambassador of our planet to enter the vastness of space. While flying weightless above Earth’s surface, Yuri Gagarin witnessed a spectacular view of home — forests, deserts, and great plains were surrounded by expansive oceans. Upon viewing the thin blue line of the atmosphere, Gagarin became the first of our inquisitive species to see our planet as it truly is — a vibrant, geologically active world circling a star. We at Penny4NASA urge you to honor the memory of this brave man, as his Vostok 1 mission was the catalyst for every manned spaceflight adventure to date.