riekod

Latest Posts by riekod

Artistic conception of the auroras os Saturn and Earth (jupiter’s image is real - ultraviolet) Instagram: wonders_of_the_cosmos

Living near the Rocky Mountains, it’s not unusual to look up and find the sky striped with lines of clouds. Such wave clouds are often formed on the lee side of mountains and other topography. But even in the flattest plains, you can find clouds like these at times. That’s because the internal waves necessary to create the clouds can be generated by weather fronts, too.

Imagine a bit of atmosphere sitting between a low-pressure zone and a high-pressure zone. This will be an area of convergence, where winds flow inward and squeeze the fluid parcel in one direction before turning 90 degrees and stretching it in the perpendicular direction. The result is a sharpening of any temperature gradient along the interface. This is the weather front that moves in and causes massive and sudden shifts in temperature. 

On one side of the front, warm air rises. Then, as it loses heat and cools, it sinks down the cold side of the front. The sharper the temperature differences become, the stronger this circulation gets. If the air is vertically displaced quickly enough, it will spontaneously generate waves in the atmosphere. With the right moisture conditions, those waves create visible clouds at their crests, as seen here. For more on the process, check out this article over at Physics Today. (Image credit: W. Velasquez; via Physics Today)

Drops that impact a very hot surface will surf on their own vapor, and ones that hit a very cold surface will freeze almost immediately. But what happens when the temperature differences aren’t so extreme? Scientists explored this (above) by dropping room-temperature water droplets onto a cool surface – one warmer than the freezing point but cooler than the dew point at which water condenses. 

They found that impacting drops formed a triple halo of condensate (right).  The first and brightest ring forms at the radius of the drop’s maximum extent during impact. The second band forms from water vapor that leaves the droplet at impact. As that vapor cools, it condenses into a second band. The final, dimmest band forms as the droplet stabilizes and cools. It’s the result of water vapor near the droplet continuing to cool and condense. (Image and research credit: Y. Zhao et al.; via Nature News; submitted by Kam-Yung Soh)

[Mathematics is] a very powerful and effective language invented by humans to describe and discover patterns in nature. When we perceive beauty in the mathematics, I think what we’re really perceiving is an underlying beauty in nature itself.

Jim Baggott, Quantum Space

A single-celled organism dying

Take a mixture of a viscous liquid – like clay mud – and squeeze it between two glass plates and you’ll create a mostly-round layer of liquid. As you pry the two glass plates apart, air will push its way into that layer, forcing through the mud in a dendritic pattern. This is called the Saffman-Taylor instability or viscous fingering. It occurs because the interface between the air and mud is unstable.  (Image and video credit: amàco et al.)

SNR 0509-67.5: a remnant from a supernova in the Large Magellanic Cloud

Credit: NASA/ESA/Hubble Team/Kevin M. Gill

List of extrasolar candidates for liquid water

The following list contains candidates from the list of confirmed objects that meet the following criteria:

Confirmed object orbiting within a circumstellar habitable zone of Earth mass or greater (because smaller objects may not have the gravitational means to retain water) but not a star

Has been studied for more than a year

Confirmed surface with strong evidence for it being either solid or liquid

Water vapour detected in its atmosphere

Gravitational, radio or differentation models that predict a wet stratum

55 Cancri f

With a mass half that of Saturn, 55 Cancri f is likely to be a gas giant with no solid surface. It orbits in the so-called “habitable zone,” which means that liquid water could exist on the surface of a possible moon. ]

Proxima Centauri b

Proxima Centauri b is an exoplanet orbiting in the habitable zone of the red dwarfstar Proxima Centauri, which is the closest star to the Sun and part of a triple star system. It is located about 4.2 light-years from Earth in the constellation of Centaurus, making it the closest known exoplanet to the Solar System.

Gliese 581c

Gliese 581c gained interest from astronomers because it was reported to be the first potentially Earth-like planet in the habitable zone of its star, with a temperature right for liquid water on its surface, and by extension, potentially capable of supporting extremophile forms of Earth-like life.

Gliese 667 Cc

Gliese 667 Cc is an exoplanet orbiting within the habitable zone of the red dwarf star Gliese 667 C, which is a member of the Gliese 667 triple star system, approximately 23.62 light-years away in the constellation of Scorpius.

Gliese 1214 b

Gliese 1214 b is an exoplanet that orbits the star Gliese 1214, and was discovered in December 2009. Its parent star is 48 light-years from the Sun, in the constellation Ophiuchus. As of 2017, GJ 1214 b is the most likely known candidate for being an ocean planet. For that reason, scientists have nicknamed the planet “the waterworld”.

HD 85512 b

HD 85512 b is an exoplanet orbiting HD 85512, a K-type main-sequence star approximately 36 light-years from Earth in the constellation of Vela.

Due to its mass of at least 3.6 times the mass of Earth, HD 85512 b is classified as a rocky Earth-size exoplanet (<5M⊕) and is one of the smallest exoplanets discovered to be just outside the inner edge of the habitable zone.

MOA-2007-BLG-192Lb

MOA-2007-BLG-192Lb, occasionally shortened to MOA-192 b, is an extrasolar planet approximately 3,000 light-years away in the constellation of Sagittarius. The planet was discovered orbiting the brown dwarf or low-mass star MOA-2007-BLG-192L. At a mass of approximately 3.3 times Earth, it is one of the lowest-mass extrasolar planets at the time of discovery. It was found when it caused a gravitational microlensing event on May 24, 2007, which was detected as part of the MOA-II microlensing survey at the Mount John University Observatory in New Zealand.

Kepler-22b

Kepler-22b, also known by its Kepler object of interest designation KOI-087.01, is an extrasolar planet orbiting within the habitable zone of the Sun-like star Kepler-22. It is located about 587 light-years (180 pc) from Earth in the constellation of Cygnus. source

Earthrise, Apollo Moon Landing 

One of the challenges in studying tornadoes is being in the right place at the right time. In that regard, storm chaser Brandon Clement hit the jackpot earlier this week when he captured this footage of a tornado near Sulphur, Oklahoma from his drone. He was able to follow the twister for several minutes until it apparently dissipated. 

Scientists are still uncertain exactly how tornadoes form, but they’ve learned to recognize the key ingredients. A strong variation of wind speed with altitude can create a horizontally-oriented vortex, which a localized updraft of warm, moist air can lift and rotate to vertical, birthing a tornado. These storms most commonly occur in the central U.S. and Canada during springtime, and researchers are actively pursing new ways to predict and track tornadoes, including microphone arrays capable of locating them before they fully form. (Image and video credit: B. Clement; via Earther)

Blue Straggler Stars in Globular Cluster M53 

Image Credit: ESA/Hubble, NASA

420 more like 440 lol stay in tune, guys

It’s sad how much of what is taught in school is useless to over 99% of the population.

There are literally math concepts taught in high school and middle school that are only used in extremely specialized fields or that are even so outdated they aren’t used anymore!

How Big is Our Galaxy, the Milky Way?

When we talk about the enormity of the cosmos, it’s easy to toss out big numbers – but far harder to wrap our minds around just how large, how far and how numerous celestial bodies like exoplanets – planets beyond our solar system – really are.

So. How big is our Milky Way Galaxy?

We use light-time to measure the vast distances of space.

It’s the distance that light travels in a specific period of time. Also: LIGHT IS FAST, nothing travels faster than light.

How far can light travel in one second? 186,000 miles. It might look even faster in metric: 300,000 kilometers in one second. See? FAST.

How far can light travel in one minute? 11,160,000 miles. We’re moving now! Light could go around the Earth a bit more than 448 times in one minute.

Speaking of Earth, how long does it take light from the Sun to reach our planet? 8.3 minutes. (It takes 43.2 minutes for sunlight to reach Jupiter, about 484 million miles away.) Light is fast, but the distances are VAST.

In an hour, light can travel 671 million miles. We’re still light-years from the nearest exoplanet, by the way. Proxima Centauri b is 4.2 light-years away. So… how far is a light-year? 5.8 TRILLION MILES.

A trip at light speed to the very edge of our solar system – the farthest reaches of the Oort Cloud, a collection of dormant comets way, WAY out there – would take about 1.87 years.

Our galaxy contains 100 to 400 billion stars and is about 100,000 light-years across!

One of the most distant exoplanets known to us in the Milky Way is Kepler-443b. Traveling at light speed, it would take 3,000 years to get there. Or 28 billion years, going 60 mph. So, you know, far.

SPACE IS BIG.

Read more here: go.nasa.gov/2FTyhgH

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

The first image ever taken of a supermassive black hole

For the first time ever, humanity can gaze at an actual photograph of a supermassive black hole. It’s an achievement that took supercomputers, eight telescopes stationed on five continents, hundreds of researchers, and vast amounts of data to accomplish. The results from this project were announced today.

Photo credit: The Event Horizon Telescope

The Unreasonable Effectiveness of Mathematics in  the Natural Sciences

Scholars have often expressed astonishment for how well mathematics works to describe our physical world. In 1960, Eugene Wigner published an article with the title above commenting that

…the mathematical formulation of the physicist’s often crude experience leads, in an uncanny number of cases, to an amazingly accurate description of a large class of phenomena.

Here are some others’ thoughts:

The most incomprehensible thing about the universe is that it is comprehensible.

— Albert Einstein

Physics is mathematical not because we know so much about the physical world, but because we know so little; it is only its mathematical properties that we can discover.

— Bertrand Russell

How can it be that mathematics, being after all a product of human thought which is independent of experience, is so admirably appropriate to the objects of reality?

— Albert Einstein

Our physical world doesn’t have just some mathematical properties, it has only mathematical properties.

— Max Tegmark

Physicists may have fallen prey to a false dichotomy between mathematics and physics. It’s common for theoretical physicists to speak of mathematics providing a quantitative language for describing physical reality… But maybe… math is more than just a description of reality. Maybe math is reality.

— Brian Greene

More info at  https://en.wikipedia.org/wiki/The_Unreasonable_Effectiveness_of_Mathematics_in_the_Natural_Sciences

Arp 194: Merging Galaxy Group via NASA

this morning NASA abandoned their mars rover Opportunity (aka Oppy) because it (she) got hit by a storm on Mars and it knocked her camera and wheels out and her last words to the team were “my battery is low and it is getting cold”. I know she’s a machine but I’m devastated. Oppy is the one who discovered water on Mars. RIP oppy ily space baby

The Opportunity to Rove on Mars! 🔴

Today, we’re expressing gratitude for the opportunity to rove on Mars (#ThanksOppy) as we mark the completion of a successful mission that exceeded our expectations.  

Our Opportunity Rover’s last communication with Earth was received on June 10, 2018, as a planet-wide dust storm blanketed the solar-powered rover’s location on the western rim of Perseverance Valley, eventually blocking out so much sunlight that the rover could no longer charge its batteries. Although the skies over Perseverance cleared, the rover did not respond to a final communication attempt on Feb. 12, 2019.

As the rover’s mission comes to an end, here are a few things to know about its opportunity to explore the Red Planet.

90 days turned into 15 years!

Opportunity launched on July 7, 2003 and landed on Mars on Jan. 24, 2004 for a planned mission of 90 Martian days, which is equivalent to 92.4 Earth days. While we did not expect the golf-cart-sized rover to survive through a Martian winter, Opportunity defied all odds as a 90-day mission turned into 15 years!

The Opportunity caught its own silhouette in this late-afternoon image taken in March 2014 by the rover’s rear hazard avoidance camera. This camera is mounted low on the rover and has a wide-angle lens.

Opportunity Set  Out-Of-This-World Records

Opportunity’s achievements, including confirmation water once flowed on Mars. Opportunity was, by far, the longest-lasting lander on Mars. Besides endurance, the six-wheeled rover set a roaming record of 28 miles.

This chart illustrates comparisons among the distances driven by various wheeled vehicles on the surface of Earth’s moon and Mars. Opportunity holds the off-Earth roving distance record after accruing 28.06 miles (45.16 kilometers) of driving on Mars.

It’s Just Like Having a Geologist on Mars

Opportunity was created to be the mechanical equivalent of a geologist walking from place to place on the Red Planet. Its mast-mounted cameras are 5 feet high and provided 360-degree two-eyed, human-like views of the terrain. The robotic arm moved like a human arm with an elbow and wrist, and can place instruments directly up against rock and soil targets of interest. The mechanical “hand” of the arm holds a microscopic camera that served the same purpose as a geologist’s handheld magnifying lens.

There’s Lots to See on Mars

After an airbag-protected landing craft settled onto the Red Planet’s surface and opened, Opportunity rolled out to take panoramic images. These images gave scientists the information they need to select promising geological targets that tell part of the story of water in Mars’ past. Since landing in 2004, Opportunity has captured more than 200,000 images. Take a look in this photo gallery.

From its perch high on a ridge, the Opportunity rover recorded this image on March 31, 2016 of a Martian dust devil twisting through the valley below. The view looks back at the rover’s tracks leading up the north-facing slope of “Knudsen Ridge,” which forms part of the southern edge of “Marathon Valley

There Was Once Water on Mars?!

Among the mission’s scientific goals was to search for and characterize a wide range of rocks and soils for clues to past water activity on Mars. In its time on the Red Planet, Opportunity discovered small spheres of the mineral hematite, which typically forms in water. In addition to these spheres that a scientist nicknamed “blueberries,” the rover also found signs of liquid water flowing across the surface in the past: brightly colored veins of the mineral gypsum in rocks, for instance, which indicated water flowing through underground fractures.

The small spheres on the Martian surface in this close-up image are near Fram Crater, visited by the Opportunity rover in April 2004.

For more about Opportunity’s adventures and discoveries, see: https://go.nasa.gov/ThanksOppy.

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

5 Facts About Earth's Radiation Donuts 🍩

Did you know that our planet is surrounded by giant, donut-shaped clouds of radiation?

Here’s what you need to know.

1. The radiation belts are a side effect of Earth’s magnetic field

The Van Allen radiation belts exist because fast-moving charged particles get trapped inside Earth’s natural magnetic field, forming two concentric donut-shaped clouds of radiation. Other planets with global magnetic fields, like Jupiter, also have radiation belts.

2. The radiation belts were one of our first Space Age discoveries

Earth’s radiation belts were first identified in 1958 by Explorer 1, the first U.S. satellite. The inner belt, composed predominantly of protons, and the outer belt, mostly electrons, would come to be named the Van Allen Belts, after James Van Allen, the scientist who led the charge designing the instruments and studying the radiation data from Explorer 1.

3. The Van Allen Probes have spent six years exploring the radiation belts

In 2012, we launched the twin Van Allen Probes to study the radiation belts. Over the past six years, these spacecraft have orbited in and out of the belts, providing brand-new data about how the radiation belts shift and change in response to solar activity and other factors.

4. Surprise! Sometimes there are three radiation belts

Shortly after launch, the Van Allen Probes detected a previously-unknown third radiation belt, created by a bout of strong solar activity. All the extra energy directed towards Earth meant that some particles trapped in our planet’s magnetic field were swept out into the usually relatively empty region between the two Van Allen Belts, creating an additional radiation belt.

5. Swan song for the Van Allen Probes

Originally designed for a two-year mission, the Van Allen Probes have spent more than six years collecting data in the harsh radiation environment of the Van Allen Belts. In spring 2019, we’re changing their orbit to bring the perigee — the part of the orbit where the spacecraft are closest to Earth — about 190 miles lower. This ensures that the spacecraft will eventually burn up in Earth’s atmosphere, instead of orbiting forever and becoming space junk.

Because the Van Allen Probes have proven to be so hardy, they’ll continue collecting data throughout the final months of the mission until they run out of fuel. As they skim through the outer reaches of Earth’s atmosphere, scientists and engineers will also learn more about how atmospheric oxygen can degrade satellite measurements — information that can help build better satellites in the future.

Keep up with the latest on the mission on Twitter, Facebook or nasa.gov/vanallenprobes.

Stellar Winds

Stellar winds are fast moving flows of material (protons, electrons and atoms of heavier metals) that are ejected from stars. These winds are characterised by a continuous outflow of material moving at speeds anywhere between 20 and 2,000 km/s.

In the case of the Sun, the wind ‘blows’ at a speed of 200 to 300 km/s from quiet regions, and 700 km/s from coronal holes and active regions.

The causes, ejection rates and speeds of stellar winds vary with the mass of the star. In relatively cool, low-mass stars such as the Sun, the wind is caused by the extremely high temperature (millions of degrees Kelvin) of the corona.

his high temperature is thought to be the result of interactions between magnetic fields at the star’s surface, and gives the coronal gas sufficient energy to escape the gravitational attraction of the star as a wind. Stars of this type eject only a tiny fraction of their mass per year as a stellar wind (for example, only 1 part in 1014 of the Sun’s mass is ejected in this way each year), but this still represents losses of millions of tonnes of material each second. Even over their entire lifetime, stars like our Sun lose only a tiny fraction of 1% of their mass through stellar winds.

In contrast, hot, massive stars can produce stellar winds a billion times stronger than those of low-mass stars. Over their short lifetimes, they can eject many solar masses (perhaps up to 50% of their initial mass) of material in the form of 2,000 km/sec winds.

These stellar winds are driven directly by the radiation pressure from photons escaping the star. In some cases, high-mass stars can eject virtually all of their outer envelopes in winds. The result is a Wolf-Rayet star.

Stellar winds play an important part in the chemical evolution of the Universe, as they carry dust and metals back into the interstellar medium where they will be incorporated into the next generation of stars. 

source (read more) + Wolf–Rayet star

The edges of this flame are black. No camera trickery, no special effects. What’s going on here is down to some interesting science and some excited electrons.

When you burn sodium it emits a monochromatic yellow/orange light. This happens because when sodium heats up, electrons in the atom’s orbitals become excited and they jump up to a higher energy level. When they drop back down to their original energy level they release a photon of light of a specific wavelength, which for sodium is yellow/orange.

As well emitting photons, sodium atoms also absorb photons of the same wavelength. That means if you have a light source emitting the same monochromatic light (like the sodium street lamp which we have here) the sodium atoms in the flame will absorb the light making the flame look dark.

For more flame filled visuals and a more detailed explantation of this phenomenon, check out our latest video https://www.youtube.com/watch?v=Kn2OyQh6o7U