Posted on by Elizabeth Howell

‘Not All Hope Is Lost’: NASA Sun Probe Silent Now For Six Weeks

Artist's conception of one of the Solar TErrestrial RElations Observatory (STEREO) spacecraft. Credit: NASA

No one knows exactly why a NASA solar probe stopped talking to Earth six weeks ago, but it’s possible the spacecraft is out of power and is drifting without a way of calling for help, the agency said in an update.

On Oct. 1, NASA suddenly lost contact with one of the two Solar TErrestrial RElations Observatory (STEREO) spacecraft, which are currently examining the far side of the Sun. The probes are considered crucial for solar forecasting, so the loss is a blow. While the STEREO-Behind probe has been mute since then, the agency says “not all hope is lost” for a recovery.

STEREO-Behind went silent after NASA deliberately reset the spacecraft. Along with its twin, STEREO-Ahead, in the coming years the spacecraft will need to reposition its antenna to avoid getting fried by the Sun. Also, there is a period where each spacecraft will need to work autonomously, because the Sun’s radio interference will make it difficult or impossible for communications to get through.

First complete image of the far side of the sun taken on June 1, 2011. Click image for larger version. Credit: NASA/STEREO.
First complete image of the far side of the sun taken on June 1, 2011. Click image for larger version. Credit: NASA/STEREO.

To prepare the spacecraft, NASA has been testing them out ahead of these events, which are called “solar conjunction operations.” STEREO-Ahead passed the tests and entered these operations in August, where it will remain until 2016. STEREO-Behind was supposed to go into this phase on Dec. 1. Preparations started Sept. 27, when STEREO-Behind was put into the same safe mode test that was used on STEREO-Ahead.

“One part of this test was to observe the firing of the spacecraft hard command loss timer, which resets the spacecraft if no commands are received after three days,” NASA wrote in an update. “The purpose of this is to correct any problems that might be preventing the spacecraft from receiving commands from the ground. While the spacecraft is out of contact on the far side of the Sun, this reset will occur every three days.”

The timer did fire as planned on Oct. 1, and the spacecraft reset as expected. However, the radio signal coming from STEREO-Behind wasn’t as strong as expected. Then, it disappeared altogether.

An artist's concept shows both STEREO surrounding the sun on opposite sides. Credit: NASA
An artist’s concept shows both STEREO surrounding the sun on opposite sides. Credit: NASA

While there’s not much information to work with, NASA says it does know a few things. Before the reset, information or telemetry from the spacecraft showed it was working fine. After the reset, though, they could tell the inertial measurement unit (IMU) was turned on. This is unusual, and shows that the guidance system’s star tracker hadn’t picked up its guide stars as expected.

“This is not unexpected—there have been other occasions when it took the star tracker several minutes, or even a few days, to start determining the spacecraft orientation based on star images,” NASA said.

“In fact, on Sept. 28, as part of the same test sequence, the spacecraft was reset, and it took 12 minutes for the star tracker to start providing an attitude solution. When the star tracker is ofline, the spacecraft will automatically turn on the IMU to provide rotational rate information.”

Deployment of STEREO Spacecraft Panels. Credit: 2002-Johns Hopkins University Applied Physics Laboratory. Credit: Dr C.J.Eyles, University of Birmingham
Deployment of STEREO Spacecraft Panels. Credit: 2002-Johns Hopkins University Applied Physics Laboratory. Credit: Dr C.J.Eyles, University of Birmingham

NASA thinks the star tracker’s struggles would explain why the radio signal wasn’t as strong as expected, because the spacecraft’s high-gain antenna wasn’t aimed at Earth properly. But there’s more — it appears one of the IMU’s laser gyroscopes isn’t working and is giving “bad data to the attitude control system”, NASA said. So now the spacecraft was facing two failures, which is tough for it to deal with, the agency added.

Did the spacecraft recognize the problem? If it did, it would have used the last backup system — five solar aspect sensors — which should have made sure the solar panels were pointed in the right direction to provide power. If not, the spacecraft might have thought it was in a roll, turned on its thrusters, and then spun itself in such a way that it could have lost sunlight power.

NASA is trying to send out commands to address all of these failure possibilities, and it emphasizes that a recovery is still possible. The Solar and Heliospheric Observatory (SOHO), for example, also lost power in 1998 when a spin put its solar panels out of reach of the Sun. However, as its orbit changed, the Sun’s light eventually fell across the panels and power was restored. The spacecraft was recovered and still works today.

Source: NASA

Posted on by Ken Kremer

Orion’s Rocket Ready to Rock n’ Roll for Critical December Test Flight

Launch teams practice countdown and fueling tests on the United Launch Alliance Delta IV Heavy rocket that will lift NASA’s Orion spacecraft on its unmanned flight test in December 2014. Credit: NASA

The huge rocket that will blast NASA’s first Orion spacecraft into orbit is ready to Rock ‘n’ Roll on a critical two orbit test flight scheduled for December.

And Orion is so big and heavy that she’s not launching on just any old standard rocket.

To blast the uncrewed Orion to orbit on its maiden mission requires the most powerful booster on Planet Earth – namely the United Launch Alliance Delta IV Heavy rocket.

Liftoff of the state-of-the-art Orion spacecraft on the unmanned Exploration Flight Test-1 (EFT-1) mission is slated for December 4, 2014, from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

Just days ago, the launch team successfully completed a countdown and wet dress rehearsal fueling test on the rocket itself – minus Orion – at launch complex 37.

The high fidelity rehearsal included fully powering up the booster and loading the tanks with cryogenic fuel and oxidizer, liquid oxygen and liquid hydrogen
The high fidelity rehearsal included fully powering up the booster and loading the tanks with cryogenic fuel and oxidizer, liquid oxygen, and liquid hydrogen

The high fidelity rehearsal included fully powering up the booster and loading the tanks with cryogenic fuel and oxidizer, liquid oxygen, and liquid hydrogen.

ULA technicians and engineers practiced the countdown on Nov. 5 which included fueling the core stages of the Delta IV Heavy rocket.

“Working in control rooms at Cape Canaveral Air Force Station in Florida, countdown operators followed the same steps they will take on launch day. The simulation also allowed controllers to evaluate the fuel loading and draining systems on the complex rocket before the Orion spacecraft is placed atop the launcher,” said NASA.

The next key mission milestone is attachment of the completed Orion vehicle stack on top of the rocket. Read more about the fully assembled Orion – here.

Today’s scheduled rollout of Orion to the launch pad for hoisting atop the rocket was scrubbed due to poor weather.

The Orion spacecraft sits inside the Launch Abort System Facility at NASA's Kennedy Space Center in Florida. The Ogive panels have been installed around the launch abort system. Credit: NASA/Jim Grossman
The Orion spacecraft sits inside the Launch Abort System Facility at NASA’s Kennedy Space Center in Florida. The Ogive panels have been installed around the launch abort system. Credit: NASA/Jim Grossman

The triple barreled Delta IV Heavy booster became the world’s most powerful rocket upon the retirement of NASA’s Space Shuttle program in 2011 and is the only rocket sufficiently powerful to launch the Orion EFT-1 spacecraft.

The first stage of the mammoth Delta IV Heavy generates some 2 million pounds of liftoff thrust.

“The team has worked extremely hard to ensure this vehicle is processed with the utmost attention to detail and focus on mission success,” according to Tony Taliancich, ULA’s director of East Coast Launch Operations.

“The Delta IV Heavy is the world’s most powerful launch vehicle flying today, and we are excited to be supporting our customer for this critical flight test to collect data and reduce overall mission risks and costs for the program.”

From now until launch technicians will continue to conduct the final processing, testing, and checkout of the Delta IV Heavy booster.

These three RS-68 engines will power each of the attached Delta IV Heavy Common Booster Cores (CBCs) that will launch NASA’s maiden Orion on the EFT-1 mission in December 2014. Credit: Ken Kremer/kenkremer.com
These three RS-68 engines will power each of the attached Delta IV Heavy Common Booster Cores (CBCs) that will launch NASA’s maiden Orion on the EFT-1 mission in December 2014. Credit: Ken Kremer/kenkremer.com

The Delta IV Heavy first stage is comprised of a trio of three Common Booster Cores (CBCs).

Each CBC measures 134 feet in length and 17 feet in diameter. They are equipped with an RS-68 engine powered by liquid hydrogen and liquid oxygen propellants producing 656,000 pounds of thrust. Together they generate 1.96 million pounds of thrust.

The first CBC booster was attached to the center booster in June. The second one was attached in early August.

Side view shows trio of Common Booster Cores (CBCs) with RS-68 engines powering the Delta IV Heavy rocket resting horizontally in ULA’s HIF processing facility at Cape Canaveral that will launch NASA’s maiden Orion on the EFT-1 mission in December 2014 from Launch Complex 37. Credit: Ken Kremer/kenkremer.com
Side view shows trio of Common Booster Cores (CBCs) with RS-68 engines powering the Delta IV Heavy rocket resting horizontally in ULA’s HIF processing facility at Cape Canaveral that will launch NASA’s maiden Orion on the EFT-1 mission in December 2014 from Launch Complex 37. Credit: Ken Kremer/kenkremer.com

This fall I visited the ULA’s Horizontal Integration Facility (HIF) during a media tour after the three CBCs had been joined together as well as earlier this year after the first two CBCs arrived by barge from their ULA assembly plant in Decatur, Alabama, located about 20 miles west of Huntsville. See my photos herein.

Orion in orbit in this artists concept. Credit: NASA

Orion in orbit in this artist’s concept. Credit: NASA

Orion is NASA’s next generation human rated vehicle that will eventually carry America’s astronauts beyond Earth on voyages venturing farther into deep space than ever before – beyond the Moon to Asteroids, Mars, and other destinations in our Solar System.

The two-orbit, four and a half hour EFT-1 flight will lift the Orion spacecraft and its attached second stage to an orbital altitude of 3,600 miles, about 15 times higher than the International Space Station (ISS) – and farther than any human spacecraft has journeyed in 40 years.

“This mission is a stepping stone on NASA’s journey to Mars,” said NASA Associate Administrator Robert Lightfoot.

The United Launch Alliance Delta-IV Heavy rocket tasked with launching NASA’s Orion EFT-1 mission being hoisted vertical atop Space Launch Complex-37B at Cape Canaveral Air Force Station in Florida on the morning of Oct. 1, 2014. Photo Credit: Alan Walters / AmericaSpace
The United Launch Alliance Delta-IV Heavy rocket tasked with launching NASA’s Orion EFT-1 mission being hoisted vertical atop Space Launch Complex-37B at Cape Canaveral Air Force Station in Florida on the morning of Oct. 1, 2014. Photo Credit: Alan Walters / AmericaSpace

.

“The EFT-1 mission is so important to NASA. We will test the capsule with a reentry velocity of about 85% of what’s expected by [astronauts] returning from Mars.”

“We will test the heat shield, the separation of the fairing, and exercise over 50% of the eventual software and electronic systems inside the Orion spacecraft. We will also test the recovery systems coming back into the Pacific Ocean.”

Stay tuned here for Ken’s continuing Orion and Earth and planetary science and human spaceflight news.

Ken Kremer

NASA’s completed Orion EFT 1 crew module loaded on wheeled transporter during move to the Payload Hazardous Servicing Facility (PHFS) on Sept. 11, 2014 at the Kennedy Space Center, FL. Credit: Ken Kremer - kenkremer.com
NASA’s completed Orion EFT 1 crew module loaded on wheeled transporter during move to the Payload Hazardous Servicing Facility (PHFS) on Sept. 11, 2014, at the Kennedy Space Center, FL. Credit: Ken Kremer – kenkremer.com
Posted on by Elizabeth Howell

‘Naked’ Comets Could Expose Solar System’s Ancient Origin Story

Two objects with comet-like orbits flew through the solar system in 2013 and 2014, but with little to no activity on their surfaces. At left is C/2013 P2 Pan-STARRS and at right, C/2014 S3 Pan-STARRS. Credit: University of Hawaii Institute for Astronomy

What’s a comet that doesn’t look like a comet? The question sounds contradictory, but astronomers believe these objects exist. As comets pass through the solar system, they bleed ice and dust as the Sun’s effects wash over their small bodies. Over time, some of the objects can keep going like ghost ships — just without the ices that used to produce a show.

There already is a class of objects called damocloids that are believed to be extinct comets, but scientists believe they have found something new with two mysterious visitors — what they call “naked” comets — from the outer Solar System.

The two objects originate from an area that astronomers term the Oort Cloud, a hypothetical collection of icy bodies that orbit as far away as 100,000 times the Earth-Sun distance (astronomical unit). Gravitational influences then kick the objects in towards the Sun and they commence orbits that can last millions of years.

When Jan Oort first proposed this concept in the 1950s, he said that some of the objects there could have only a tiny layer of ice that would immediately evaporate during the first pass in near the Sun. That’s what astronomers think they are seeing in objects C/2013 P2 Pan-STARRS and C/2014 S3 Pan-STARRS.

The familiar solar system with its 8 planets occupies a tiny space inside a large spherical shell containing trillions of comets - the Oort Cloud. Credit: Wikimedia Commons
The familiar solar system with its 8 planets occupies a tiny space inside a large spherical shell containing trillions of comets – the Oort Cloud. Credit: Wikimedia Commons

“Objects on long-period orbits like this usually exhibit cometary tails, for example Comet ISON and Comet Hale Bopp, so we immediately knew this object was unusual,” stated Karen Meech, an astronomer at the University of Hawaii at Manoa who led the research. “I wondered if this could be the first evidence of movement of solar system building blocks from the inner solar system to the Oort Cloud.”

The automated Pan STARRS1 survey telescope found C/2013 P2 in August 2013, with astronomers remarking its orbit resembled that of a comet. But, C/2013 P2’s surface was quiet. A second look the next month with the 8-meter Gemini North telescope in Hawaii revealed a little bit of light and a dusty tail. The object stayed at about the same brightness, even when it got to its closest approach to the Sun (2.8 AU) in February 2014.

After the comet swung around the Sun and telescopes could look at it again, examinations with the Gemini North telescope found something weird: the object’s spectrum looked red. This makes it look more like a Kuiper Belt object — something that roams in shallower waters in the Solar System, beyond Neptune’s orbit — than a typical comet or asteroid.

While results were still being analyzed, in September a NASA survey found an object with curiously similar properties: C/2014 S3. When it was found, the object had already passed its closest approach to the Sun in August. But from analyzing the orbit, the scientists saw it had come to only within 2 AU. Also, the first observations showed barely a tail at all.

Distribution of Kuiper belt objects (green), along with various other outer Solar System bodies, based on data from the Minor Planet Center. [Credit: Minor Planet Center; Murray and Dermott]
Distribution of Kuiper belt objects (green), along with various other outer Solar System bodies, based on data from the Minor Planet Center. [Credit: Minor Planet Center; Murray and Dermott]
A closer examination with the Canada-France-Hawaii Telescope revealed a mystery: the spectrum was more blue than red, hinting at materials similar to what you would find in the inner Solar System. The team says this could be a new class of objects altogether.

“I’ll be thrilled if this object turns out to have a surface composition similar to asteroids in the inner part of the asteroid belt.  If this is the case, it will be remarkable for a body found so far out in the Solar System,” stated Meech.

“There are several models that try to explain how the planets grew in the early Solar System, and some of these predict that material formed close to the sun could have been thrown outward into the outer Solar System and Oort Cloud, where it remains today. Maybe we are finally seeing that evidence.”

Results were presented today (Nov. 10) at the Division of Planetary Sciences meeting of the American Astronomical Society in Tucson, Arizona. A press release did not say if the research is peer-reviewed, or state publication plans.

Source: University of Hawaii Institute for Astronomy

Posted on by Susie Murph

Carnival of Space #379

Carnival of Space. Image by Jason Major.
Carnival of Space. Image by Jason Major.

This week’s Carnival of Space is hosted by Nicole Gugliucci at her Cosmoquest blog.

Click here to read Carnival of Space #379

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

Posted on by Elizabeth Howell

Incredible Snow-Dragging Spaceship Landing From The Space Station

Tracks in the snow mark Expedition 41's landing from the space station Nov. 9, 2014. Credit: NASA/Bill Ingalls

Check out that landing mark! A Soyuz spacecraft carrying three people touched down safely in remote Kazakhstan late Sunday (EDT) and went for a brief sleigh ride in the snow, as you can see from the drag marks on the landscape.

The flawless landing included the Expedition 40/41 crew members of Reid Wiseman (NASA), Alexander Gerst (European Space Agency) and Maxim Suraev (Roscosmos), who spent 165 days in space, mainly living on the International Space Station. Check out some more landing pictures and video below.

Alexander Gerst, an astronaut from the European Space Agency, does a fist pump shortly after the safe Expedition 41 landing Nov. 9, 2014. Credit: ESA–S. Corvaja, 2014
Alexander Gerst, an astronaut from the European Space Agency, does a fist pump shortly after the safe Expedition 41 landing Nov. 9, 2014. Credit: ESA–S. Corvaja, 2014

Posted on by Brian Koberlein

Why Doesn’t The Sun Steal The Moon?

On Sept. 18, 1977, Voyager 1 took three images of the Earth and Moon that were combined into this one image. The moon is artificially brightened to make it show up better. Credit: NASA

The Sun has so much more mass than the Earth. So, so, so much more mass. Almost everything in the Solar System is orbiting the Sun, and yet, the Moon refuses to leave our side. What gives?

The Sun contains 99.8% of the entire mass of the Solar System. It looks to us like everything seems to orbit the Sun, so why doesn’t the Sun capture the Moon from Earth like a schoolyard bully snatching the Earth’s lunch money. That would make sense right? It all fits in with our skewed view of social hierarchy based on an entities volume.

Good news! It’s already happened, In a way. The Sun has already captured the Moon. If you look at the orbit of the Moon, it orbits the Sun similar to the way Earth does. Normally the motion of the Moon around the Sun is drawn as a kind of Spirograph pattern, but its actual motion is basically the same orbit as Earth with a small wobble to it.

The Moon also orbits the Earth. You might think this is because the Earth is much closer to the Moon than the Sun. After all, the strength of gravity depends not only on the mass of an object, but also on its distance from you. But this isn’t the case. The Sun is about 400 times more distant from the Moon than the Earth, but the Sun is about 330,000 times more massive.

If you’re up for some napkin calculations, you little mathlete, by using Newton’s law of gravity, you find that even with its greater distance, the Sun pulls on the Moon about twice as hard as the Earth does.
So why can’t the Moon escape the Earth?

In order to escape the gravitational pull of a body, you need to be moving fast enough *relative to that body* to escape its pull. This is known as the escape velocity of the object.

It takes two to tango. The moon’s gravity raises a pair of watery bulges in the Earth’s oceans creating the tides, while Earth's gravity stretches and compresses the moon to warm its interior. Illustration: Bob King
It takes two to tango. The moon’s gravity raises a pair of watery bulges in the Earth’s oceans creating the tides, while Earth’s gravity stretches and compresses the moon to warm its interior. Illustration: Bob King

So, yes, the Sun is totally trying to rip the Moon away from the Earth, but the Earth is super clingy.
The speed of the Moon around the Earth is about 1 km/s. At the Moon’s distance from the Earth, the escape velocity is about 1.2 km/s. The Moon simply isn’t moving fast enough to escape the Earth.

Man, those numbers sure are close. I wonder if we could kickstart a rocket to stick on the side? So, even though the Moon can’t escape the Earth, it is gradually moving away. This is due to the tidal interactions between the Earth and Moon, which we talk about another video we’ll link at the end of this one.

So even though the Moon will never escape the Earth, it will continue to move away. So, what do you think? What kind of devious project should we start to get the Moon that little boost so it finally escapes the clingy Earth and all its clingy Klingon clingyness? Tell us in the comments below.

And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!

Posted on by Matt Williams

What Did Isaac Newton Discover?

Godfrey Kneller's 1689 portrait of Isaac Newton at age 46. Image credit: Isaac Newton Insitute

Isaac Newton – who lived from December 25th, 1642, to March 20th, 1727 – was an English scientist, mathematician, and “natural philosopher”. In his time, he played a vital role in the Scientific Revolution, helping to advance the fields of physics, astronomy, mathematics and the natural sciences. From this, he established a legacy that would dominate the sciences for the next three centuries.

In fact, the term “Newtonian” came to be used by subsequent generations to describe bodies of knowledge that owed their existence to his theories. And because of his extensive contributions, Sir Isaac Newton is regarded as one of the most influential scholars in the history of science. But what exactly did he discover?

Newton’s Three Laws of Motion:

For starters, his magnum opus – Philosophiæ Naturalis Principia Mathematica (“Mathematical Principles of Natural Philosophy”), which was first published in 1687 – laid the foundations for classical mechanics. In it, he formulated his Three Laws of Motion, which were derived from Johann Kepler’s Laws of Planetary Motion and his own mathematical description of gravity.

William Blake's Newton (1795), depicted as a divine geometer. Image Credit: William Blake Archive/Wikipedia
William Blake’s Newton (1795), depicting him as a divine geometer. Image Credit: William Blake Archive/Wikipedia

The first law, known as the “law of inertia”, states that: “An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force.” The second law states that acceleration is produced when a force acts on a mass – ergo, the greater the mass of the object, the greater the force required to accelerate it. The third and final law states that “for every action, there is an equal but opposite reaction”.

Universal Gravitation:

He also formulated his law of Universal Gravitation in the Principia, which states that every point mass attracts every single other point mass by a force pointing along the line intersecting both point. According to his calculations, this force is proportional to the product of the two masses and inversely proportional to the square of the distance between them. The formula for this theory can be expressed as:

F = G frac{m_1 m_2}{r^2}

Newton would go on to use these principles to account for the trajectories of comets, the tides, the precession of the equinoxes, and other astrophysical phenomena. This effectively removed the last doubts about the validity of the heliocentric model of the cosmos which argued that the Sun (not the Earth) was at the center of the planetary system. His work also demonstrated that the motion of objects on Earth and of celestial bodies could be described by the same principles.

Sapling of the reputed original tree that inspired Sir Isaac Newton to consider gravitation. Credit: Wikipedia Commons/Loodog
Sapling of the reputed original tree that inspired Sir Isaac Newton to consider gravitation. Credit: Wikipedia Commons/Loodog

Though Newton’s inspiration for his theories on gravity are often attributed to the “Apple Incident” – i.e. where he watched an apple fall from a tree – the story is considered apocryphal by modern sources who argue that he came to his conclusions over time. However, Newton himself described the incident, and contemporaries of his defend this assertion.

Shape of the Earth:

Additional contributions include his prediction that the Earth was likely shaped as an “oblate spheroid” – i.e. a sphere that experienced flattening at the poles. This theory would later be vindicated by the measurements of Maupertuis, La Condamine, and others. This in turn helped convince most Continental European scientists of the superiority of Newtonian mechanics over the earlier system of Descartes.

In terms of mathematics, he contributed to the study of power series, generalized the binomial theorem to non-integer exponents, developed Newton’s method for approximating the roots of a function, and classified most of the cubic plane curves. He also shares credit with Gottfried Leibniz for the development of calculus.

These discoveries represented a huge leap forward for the fields of math, physics, and astronomy, allowing for calculations that more accurately modeled the behavior of the universe than ever before.

Optics:

In 1666, Newton began contributing to the field of optics, first by observing that color was a property of light by measuring it through a prism. From 1670 to 1672, he lectured at the University of Cambridge on optics and investigated the refraction of light, demonstrating that the multicolored spectrum produced by a prism could be recomposed into white light by a lens and a second prism.

Sunlight passing through a prism. Image credit: NASA
Sunlight passing through a prism. Image credit: NASA

As a result of his research, he came to theorize that color is the result of objects interacting with already-colored light rather than objects generating the color themselves, which is known as Newton’s theory of color.

In addition, he concluded that the lens of any refracting telescope would suffer from the dispersion of light into colors (chromatic aberration). As a proof of the concept, he constructed a telescope using a mirror as the objective to bypass that problem. This was the first known functional reflecting telescope in existence, the design of which is now known as a Newtonian telescope.

Other Achievements:

He also formulated an empirical law of cooling, studied the speed of sound, and introduced the notion of a Newtonian fluid. This term is used to describe any fluid where the viscous stresses arising from its flow, at every point, are linearly proportional to the rate of change of its deformation over time.

Beyond his work in mathematics, optics and physics, he also devoted a significant amount of time studying Biblical chronology and alchemy, but most of his work in these areas remained unpublished until long after his death.

So what did Isaac Newton discover? Theories that would dominate the fields of science, astronomy, physics and the natural world for centuries to come. His ideas would go on to influence such luminaries as Joseph-Louis Lagrange and Albert Einstein, the latter of whom is the only scientists believed to have left a comparable legacy.

We have written many interesting articles about Sir Isaac Newton here at Universe Today. Here’s Who was Sir Isaac Newton?, What did Isaac Newton Invent?, Who Discovered Gravity?, What is Absolute Space?, What is the Gravitational Constant?

There are other resources on the internet if you want to learn more about Isaac Newton. This UK site has some great info on his discoveries. You can also check out the PBS website.

You can also check out Astronomy Cast. Episode 44 Einstein’s Theory of Relativity is particularly interesting.

Sources:

Posted on by Shannon Hall

A Snapshot of a Galactic Crash

This image combines NASA/ESA Hubble Space Telescope observations with data from the Chandra X-ray Observatory. As well as the electric blue ram pressure stripping streaks seen emanating from ESO 137-001, a giant gas stream can be seen extending towards the bottom of the frame, only visible in the X-ray part of the spectrum. Credit: NASA, ESA, CXC

Some galaxies shine with a red ghostly glow. Once these galaxies stop forming new stars, they can only host long-lived stars with low masses and red optical colors. Astronomers often call these ghostly galaxies “red and dead.” But the basics behind why some form so quickly is still a mystery.

“It is one of the major tasks of modern astronomy to find out how and why galaxies in clusters evolve from blue to red over a very short period of time,” said lead author Michele Fumagalli from Durham University in a news release. “Catching a galaxy right when it switches from one to the other allows us to investigate how this happens.”

And that’s exactly what Fumagalli and colleagues did.

The team used ESO’s Multi Unit Spectroscopic Explorer (MUSE) instrument mounted on the 8-meter Very Large Telescope. With this instrument, astronomers collect 90,000 spectra every time they look at an object, allowing them to gain a detailed map of the object’s motion through space.

This chart shows the location of the distant galaxy ESO 137-001 in the constellation of Triangulum Australe (The Southern Triangle). This is a rich area of the sky close to the Milky Way, but this galaxy is faint and needs a large telescope to be visible. Credit: ESO, IAU and Sky & Telescope
The location of the distant galaxy ESO 137-001. Credit: ESO / IAU / Sky & Telescope

The target, ESO 137-001, is a spiral galaxy 200 million light-years away in the constellation better known as the Southern Triangle. But more importantly, it’s currently hurtling toward the Norma Cluster and embarking on a grand galactic collision.

ESO 137-001 is being stripped of most of its gas due to a process called ram-pressure stripping. As the galaxy falls into the galaxy cluster, it feels a headwind, much as a runner feels a wind on even the stillest day. At times this can compress the gas enough to spark star formation, but if it’s too intense then the gas is stripped away, leaving a galaxy that’s empty of the material needed to form new stars.

So the galaxy is in the midst of a brilliant transformation, changing from a blue gas-rich galaxy to a red gas-poor galaxy.

The observations show that the outskirts of the galaxy are already completely devoid of gas. Here the stars and matter are more thinly spread, and gravity has a relatively week hold over the gas. So it’s easier to push the gas away.

In fact, dragging behind the galaxy are 200,000 light-year-long streams of gas that have already been lost, making the galaxy look like a jellyfish trailing its tentacles through space. In these streamers, the gas is turbulent enough to compress small pockets of gas and therefore actually ignite star formation.

The center of the galaxy, however, is not yet devoid of gas because the gravitational pull is strong enough to hold out much longer. But it will only take time until all of the galactic gas is swept away, leaving ESO 137-001 red and dead.

Surprisingly the new MUSE observations show the gas trailing behind continues to rotate in the same way that the galaxy does. Furthermore, the rotation of stars at the center of the galaxy remains unhindered by the great fall.

Astronomers remain unsure why as this is only a snapshot of one galactic crash, but soon MUSE and other instruments will pry more out of the cosmic shadows.

The results will be published in the journal Monthly Notices of the Royal Astronomical Society and are available online.