Reinventing The Wheel

A slow-motion animation of the Crab Pulsar taken at 800 nm wavelength (near-infrared) using a Lucky Imaging camera from Cambridge University, showing the bright pulse and fainter interpulse.

Credit: Cambridge University Lucky Imaging Group

False color image of Uranus taken with the Hale Telescope and the Palomar Observatory. The rings are the red pieces.

Image credit: Palomar Observatory & Hale telescope

5 Questions You Were Too Embarrassed To Ask About The Expanding Universe

“5.) Are there galaxies moving away faster than the speed of light, and isn’t that forbidden? From our point of view, the space in between us and any distant point is expanding. The farther away something is, the faster it appears to recede from us. Even if the expansion rate were tiny, an object far enough away would eventually cross that threshold of any finite speed, since an expansion rate (a speed-per-distance) multiplied by a great enough distance will give you a speed as fast as you want. But this is okay in General Relativity! The law that nothing can travel faster than the speed of light only applies to an object’s motion through space, not to the expansion of space itself. In reality, the galaxies themselves only move around at speeds that are hundreds or thousands of km/s, much lower than the 300,000 km/s speed limit set by the speed of light. It’s the expansion of the Universe that causes this recession and the redshift, not a true galactic motion.”

The idea that the spatial fabric of the Universe itself is expanding, and that’s what’s behind the observed relationship between redshift and distance has long been controversial, and also long-misunderstood. After all, if more distant objects appear to recede more quickly, couldn’t there be a different explanation, like an explosion that flung many things outward? As it turns out, this isn’t a mere difference in interpretation, there are observations we can make that tell us the answer! The Universe is not expanding ‘into’ anything, despite what your intuition might tell you. The Hubble ‘constant’ isn’t actually a constant, but is rather decreasing as time goes on. The Universe looks like it’s going to expand forever, but even that scientific conclusion is subject to revision depending on what data shows in the future. And although 97% of the galaxies in the Universe are already unreachable, it isn’t a violation of relativity or a faster-than-light phenomenon that’s to blame.

Come learn the answers to five questions about the expanding Universe that many are too embarrassed to ask!

Solar System: 10 Things to Know This Week...Halloween Edition!

This week, we’re getting into the Halloween spirit with 10 spooktacular things to let your imagination run wild. 

It’s not Halloween without our favorite scary characters, but what if they could stop bothering us Earthlings and go far, far away? We begin with where Dracula, Frankenstein, and other creepy creatures might choose to live if the galaxy were theirs to claim…

1. The dark (k)night.

The prince of darkness himself, Dracula, can finally seek sweet respite from the Sun. We think he’d love to live on a rocky planet named YZ Ceti d that orbits so close to its red star that it’s tidally locked keeping one side of the planet in perpetual nighttime and the other side in perpetual daytime, with a brilliant red sky (though we can guess which side Dracula will prefer). 

2. Where art thou, werewolves? 

Home sweet home for our furry Full Moon friends might just be on Trappist-1, a planetary system with seven planets—and where standing on one planet would mean the other planets look like six moons (some as big as our Moon in the sky). 

3. Left in the dust. 

We couldn’t think of anyone better to live on Proxima b than The Mummy. Hopefully this ancient monster can finally rest in peace on an exoplanet that scientists theorize is a desert planet once home to ancient oceans. 

4. Cloudy with a chance of Frankenstein.

One scientific experiment we’d like to conduct: whether Frankenstein would rather live on HAT-P-11b or Kepler-3b, theorized to have fierce thunderstorms and lightning. 

5. The walking dead. 

We’re pretty confident that if zombies were to pick a planet, they’d want one that shares their love of death and destruction. We think they’d feel right at home on one of the pulsar planets, which are scorched by radiation because they orbit a dead star. 

6. Rest your weary bones. 

Skeletons need look no further: Osiris, an exoplanet that’s so close to a star that it’s “losing its flesh” as the star destroys it, seems like a perfect match. 

7. Enough of the scary stuff. 

For kids out there, turn pumpkin decorating into an out-of-this-world activity with space-themed stencils, from Saturn to the Sun. 

8. Spooky sounds. 

Cassini’s radio emissions from Saturn could give creaky doors and howling winds a run for their money. Listen to the eerie audio recordings here and find more HERE.

9. Pumpkin-carve like a NASA engineer. 

NASA engineers design and build robots that can fly millions of miles to study other planets for a living—so on Halloween, they can’t help but bring that creative thinking to the grand old tradition of pumpkin carving. Take a cue from their creations with these insider tips.

10. Detective for a day. 

From blades of ice on Pluto to a fuzzy, white “bunny” photographed on Mars, become a solar system sleuth and see if you can solve the stellar mysteries in this slideshow (then compare with how scientists cracked the case). 

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

Young Stellar Grouping in Cygnus X

Cygnus X hosts many young stellar groupings. The combined outflows and ultraviolet radiation from the region’s numerous massive stars have heated and pushed gas away from the clusters, producing cavities of hot, lower-density gas.

In this 8-micron infrared image, ridges of denser gas mark the boundaries of the cavities. Bright spots within these ridges show where stars are forming today.

Credit: NASA/IPAC/MSX

Image of Saturn taken by the Cassini spacecraft in 2013

Image credit: NASA / JPL-Caltech 

What’s Up November 2017

What’s Up For November?

Dawn pairing of Jupiter and Venus, Moon shines near star clusters, meteor activity all month long!

This month binoculars will come in handy–to view the moon, star clusters, and a close pairing of Venus and Jupiter.

You can’t miss bright Venus in the predawn sky. This month Venus pairs up with Jupiter on the morning of November 13th.

The Leonids peak on a moonless November 17th. Expect no more than 10 meteors an hour around 3:00 a.m., the height of the shower.

The Northern and Southern sub-branches of the Taurid meteor shower offer sparse counts of about 5 meteors per hour, but slow, bright meteors are common.

The nearby November Orionids peak on the 28th. In contrast to the Taurids, the Orionids are swift. But don’t expect more than 3 meteors per hour.

The moon glides by three beautiful star clusters in the morning sky this month, and a pair of binoculars will allow you to see the individual stars in the clusters. Aim your binoculars at the Pleiades and the moon on the 5th.

Then aim at the Messier or M-35 cluster and the moon on the 7th and the Beehive cluster and the moon on the 10th.

Meanwhile, at dusk, catch Saturn as it dips closer to the western horizon and pairs up with Mercury on the 24th through the 28th.

Also, Comet C/2017 O1 should still be a binocular-friendly magnitude 7 or 8 greenish object in November. Use Polaris, the North Star as a guide. Look in the East to Northeast sky in the late evening.  

Watch the full What’s Up for November Video: 

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

Image of the planet Neptune seen by the space probe Voyager 2

Image credit: NASA/JPL

Tomorrow one of the most prolific and beloved spacecraft missions will come to an end when the Cassini spacecraft makes its final plunge into Saturn. After nearly 20 years in space and 13 years orbiting Saturn, the Cassini mission is close to running out of fuel. To prevent the craft from contaminating one of Saturn’s moons – which its mission revealed may harbor the ingredients for life – mission operators are instead sending it on a fatal dive into the gas giant. 

Cassini has and will continue to provide a trove of scientific insights about Saturn and its environs. It has given us front-row seats to a storm that wrapped around the entire planet. It shed new light on Saturn’s spectacular hexagonal polar vortex and showed us the beauty of auroras on other planets. Cassini also showed us that Saturn’s moon Titan has stable hydrocarbon lakes at its surface, fed by methane rains and driven by processes unfamiliar to terrestrial ones. It also gave us paths for future exploration by documenting plumes of water ejected from Enceladus’ icebound oceans.

Cassini also holds a special place in my heart. It launched while I was in middle school, reached Jupiter while I was in college, and collected data throughout my postgraduate research career. It was an inspiration for my undergraduate spacecraft mission design projects, and it provided fun and exciting fluid dynamical discoveries throughout my time writing FYFD. It’s my favorite mission (sorry, Mars rovers, New Horizons, Dawn, and Juno!) and likely to remain so for years to come.

So thank you, Cassini, and many thanks to all the scientists, engineers, and operators who’ve worked on the mission during the decades from its conception to completion. You did a hell of a job. Godspeed, Cassini! (Photo credits: NASA/JPL)

P.S. - Tonight I’ll be helping kick off the Ig Nobel Prize ceremony. You can tune into the live webcast here. The ceremony officially starts at 6 PM Eastern time, but I recommend tuning in early, especially if you want to catch my full spiel. - Nicole 

Astronomy and Astrophysics: Facts

Here is a list of some curiosities of astronomy and astrophysics. From our solar system to interstellar space.

Rings of Saturn: With an estimated local thickness of as little as 10 m and as much as 1 km, they are composed of 99.9% pure water ice with a smattering of impurities that may include tholins or silicates. The main rings are primarily composed of particles ranging in size from 1 cm to 10 m.

Valhalla (crater): Valhalla is the largest multi-ring impact crater on Jupiter’s moon Callisto and in the Solar System. It is named after Valhalla, the God Odin’s hall in Norse mythology where warriors are taken after death. 

Europa (lineae):  Europa’s most striking surface features are a series of dark streaks crisscrossing the entire globe, called lineae (English: lines). Close examination shows that the edges of Europa’s crust on either side of the cracks have moved relative to each other. The larger bands are more than 20 km (12 mi) across, often with dark, diffuse outer edges, regular striations, and a central band of lighter material. The most likely hypothesis states that the lineae on Europa may have been produced by a series of eruptions of warm ice as the Europan crust spread open to expose warmer layers beneath. The effect would have been similar to that seen in Earth’s oceanic ridges.

Tartarus Dorsa: The western part of Pluto’s northern hemisphere consists of an extensive, highly distinctive set of 500-meter-high mountains informally named Tartarus Dorsa; the spacing and shape of the mountains looks similar to scales or tree bark. 

Mountain in Ceres: Ahuna Mons is the largest mountain on the dwarf planet and asteroid Ceres. It protrudes above otherwise smooth terrain, it is not an impact feature, and it appears to be the only mountain of its kind on Ceres. Bright streaks run top to bottom on its slopes; these streaks are thought to be salt, similar to the better known Cererian bright spots, and likely resulted from cryovolcanic activity from Ceres’s interior. It is named after the traditional post-harvest festival Ahuna of the Sumi Naga people of India.

Pluto has a tenuous atmosphere consisting of nitrogen (N2), methane (CH4), and carbon monoxide (CO), which are in equilibrium with their ices on Pluto’s surface. According to the measurements by New Horizons, the surface pressure is about 1 Pa(10 μbar), roughly one million to 100,000 times less than Earth’s atmospheric pressure. It was initially thought that, as Pluto moves away from the Sun, its atmosphere should gradually freeze onto the surface; studies of New Horizons data and ground-based occultations show that Pluto’s atmospheric density increases, and that it likely remains gaseous throughout Pluto’s orbit.  

Sagittarius A*: Sagittarius A*  is a bright and very compact astronomical radio source at the center of the Milky Way, near the border of the constellations Sagittarius and Scorpius. It is part of a larger astronomical feature known as Sagittarius A. Sagittarius A* is thought to be the location of a supermassive black hole, like those that are now generally accepted to be at the centers of most spiral and elliptical galaxies.

Double Pulsar: PSR J0737−3039 is the only known double pulsar. It consists of two neutron stars emitting electromagnetic waves in the radio wavelength in a relativistic binary system. The two pulsars are known as PSR J0737−3039A and PSR J0737−3039B. It was discovered in 2003 at Australia’s Parkes Observatory by an international team led by the radio astronomer Marta Burgay during a high-latitude pulsar survey.

IC 1101: IC 1101 is a supergiant elliptical galaxy at the center of the Abell 2029 galaxy cluster, approximately 320 megaparsecs (1.04 billion light-years) from Earth. IC 1101 is among the largest known galaxies, but there is debate in the astronomical literature about how to define the size of such a galaxy.

A rogue planet (also termed an interstellar planet, nomad planet, free-floating planet, orphan planet, wandering planet, starless planet, sunless planet, or Planemo) is a planetary-mass object that orbits the galaxy center directly. Such objects have been ejected from the planetary system in which they formed or have never been gravitationally bound to any star or brown dwarf. The Milky Way alone may have billions of rogue planets.

souce: wikipedia

Image credit: NASA/JPL/SwRI, Ted Stryk, John Rowe Animations, commons.wikimedia