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Multiple Earth-Mass Rogue Planets Have Been Discovered Drifting Through the Milky Way – Universe Today

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Last year we reported on how the Roman Space Telescope’s backers hoped it would be able to detect rogue planets using a technique called “microlensing”.  Now, a team led by Iain McDonald, then at the University of Manchester, beat them to the punch by finding a few examples of Earth-sized rogue planets using data from an already aging space telescope – Kepler.

Both collecting and analyzing the data used in the study wasn’t easy though.  Kepler embarked on a two-month campaign in 2016 that had it looking at millions of stars located near the center of the Milky Way every 30 minutes.  Even with that much data, picking the signal from the noise was difficult.  

[embedded content]
UT video explaining gravitational lensing, which microlensing is a smaller example of.

They are difficult because microlensing is exhibited by tiny fluctuations in the light of stars when an object passes in front of them.  According to Dr. McDonald, about every one in a million stars in the galaxy is subject to microlensing at any point in time.  So of the million of stars towards the center of the Milky Way, several could be undergoing microlensing right now.

Those events can last anywhere from minutes to days, as it depends on the difference between the foreground object and background stars, as well as the weight of the foreground object.  Of the many microlensing events that take place facing the galactic core, only approximately 1% of them are caused by rogue planets, and the signals from those events are much smaller when compared to microlenses caused by foreground stars.

[embedded content]
Video showing what a microlensing event looks like from Earth.
Credit – David Specht / Eamonn Kerins / University of Manchester

Despite all the difficulties in collecting data with an old telescope, siphoning through all the additional data and background noise, and trying to differentiate between events caused by stars and those caused by planets, Dr. McDonald and his co-author, Eamonn Kerins were able to find 27 candidates for microlensing events. Of those, four could have potentially been caused by Earth-sized rogue planets.  

The durations of the events varied widely – from an hour and 10 days in length, and some had previously been detected using ground-based observation.  But the four that were indicative of Earth-sized exoplanets were completely novel.

[embedded content]
UT Video discussing rogue planets.

Most likely, these new potential rogue planets will be the beginning of a wave of new discoveries.  Not only is Nancy Grace specifically designed to detect rogue planets using the technique in the paper (and which Kepler was very clearly not designed for), there is an ESA mission called Euclid, that will hopefully launch sometime next year, which is also tailored to search for microlensing events.

Speculation about rogue planets has existed for decades, and while we’re getting closer to definitively saying that they do exist, these microlensing events are only tentative proof. But if confirmed, they will have a dramatic impact on our understanding of both how planets form, but also our estimates of just how many might be lurking in the vast dark between stars.

Learn More:
RAS – Kepler telescope glimpses population of free-floating planets
SciTechDaily – Mysterious Population of Rogue Planets Spotted Near the Center of Our Galaxy
Gizmodo – Astronomers Spot a Batch of Rogue Planets Near the Galactic Core

Lead Image –
Artist’s conception of a rogue planet.
Credit – A. Stelter / Wikimedia Commons

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NASA discovers double crater on the moon – CTV News

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The moon has a new double crater after a rocket body collided with its surface on March 4.

New images shared by NASA’s Lunar Reconnaissance Orbiter, which has been circling the moon since 2009, have revealed the location of the unusual crater.

The impact created two craters that overlap, an eastern crater measuring 59 feet (18 metres) across and a western crater spanning 52.5 feet (16 metres). Together, they create a depression that is roughly 91.8 feet (28 metres) wide in the longest dimension.

Although astronomers expected the impact after discovering that the rocket part was on track to collide with the moon, the double crater it created was a surprise.

Typically, spent rockets have the most mass at the motor end because the rest of the rocket is largely just an empty fuel tank. But the double crater suggests that this object had large masses at both ends when it hit the moon.

The exact origin of the rocket body, a piece of space junk that had been careening around for years, is unclear, so the double crater could help astronomers determine what it was.

The moon lacks a protective atmosphere, so it’s littered with craters created when objects like asteroids regularly slam into the surface.

This was the first time a piece of space junk unintentionally hit the lunar surface that experts know of. But craters have resulted from spacecraft being deliberately crashed into the moon.

For example, four large moon craters attributed to the Apollo 13, 14, 15 and 17 missions are all much larger than each of the overlapping craters created during the March 4 impact. However, the maximum width of the new double crater is similar to the Apollo craters.

UNCLEAR ORIGIN

Bill Gray, an independent researcher focused on orbital dynamics and the developer of astronomical software, was first to spot the trajectory of the rocket booster.

Gray had initially identified it as the SpaceX Falcon rocket stage that launched the US Deep Space Climate Observatory, or DSCOVR, in 2015 but later said he’d gotten that wrong and it was likely from a 2014 Chinese lunar mission — an assessment NASA agreed with.

However, China’s Ministry of Foreign Affairs denied the booster was from its Chang’e-5 moon mission, saying that the rocket in question burned up on reentry to Earth’s atmosphere.

No agencies systematically track space debris so far away from Earth, and the confusion over the origin of the rocket stage has underscored the need for official agencies to monitor deep-space junk more closely, rather than relying on the limited resources of private individuals and academics.

However, experts say that the bigger challenge is the space debris in low-Earth orbit, an area where it can collide with functioning satellites, create more junk and threaten human life on crewed spacecraft.

There are at least 26,000 pieces of space junk orbiting Earth that are the size of a softball or larger and could destroy a satellite on impact; over 500,000 objects the size of a marble — big enough to cause damage to spacecraft or satellites; and over 100 million pieces the size of a grain of salt, tiny debris that could nonetheless puncture a spacesuit, according to a NASA report issued last year.

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7 Amazing Dark Sky National Parks – AARP

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James Ronan/Getty Images/Steve Burns

Great Basin, Arches, and Voyageurs National Park

Can’t afford to join a commercial space mission offered by Jeff Bezos or Richard Branson? Consider the next best thing: seeing a starry, starry night in a sea of darkness, unimpeded by artificial light, at one of the International Dark Sky Parks in the U.S. It’s a rare treat, since light pollution prevents nearly 80 percent of Americans from seeing the Milky Way from their homes.

The International Dark-Sky Association (IDSA) has certified 14 of the nation’s 63 national parks as dark sky destinations. So visitors can take full advantage of such visibility, many of them offer specialized after-dark programs, from astronomy festivals and ranger-led full-moon walks to star parties and astrophotography workshops. If you prefer to stargaze on your own at a park, the National Park Service recommends bringing a pair of 7-by-50 binoculars, a red flashlight, which enhances night vision, and a star chart, which shows the arrangement of stars in the sky.

Here are seven of the IDSA-certified parks where you can appreciate how the heavens looked from the Earth before the dawn of electric light.




AARP Membership -Join AARP for just $9 per year when you sign up for a 5-year term

Join today and save 43% off the standard annual rate. Get instant access to discounts, programs, services, and the information you need to benefit every area of your life. 



Award-winning travel writer Veronica Stoddart is the former travel editor of USA Today. She has written for dozens of travel publications and websites.​​

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A Mystery Rocket Left A Crater On The Moon – Forbes

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While we think of the moon as a static place, sometimes an event happens that reminds us that things can change quickly.

On March 4, a human-made object (a rocket stage) slammed into the moon and left behind a double crater, as seen by NASA’s Lunar Reconnaissance Orbiter (LRO) mission.

Officials announced June 23 that they spotted a double crater associated with the event. But what’s really interesting is there’s no consensus about what kind of rocket caused it.

China has denied claims that the rocket was part of a Long March 3 rocket that launched the country’s Chang’e-5 T1 mission in October 2014, although the orbit appeared to match. Previous speculation suggested it might be from a SpaceX rocket launching the DISCOVR mission, but newer analysis has mostly discredited that.

On a broader scale, the value of LRO observations like this is showing how the moon can change even over a small span of time. The spacecraft has been in orbit there since 2009 and has spotted numerous new craters since its arrival.

It’s also a great spacecraft scout, having hunted down the Apollo landing sites from orbit and also having tracked down a few craters from other missions that slammed into the moon since the dawn of space exploration.

It may be that humans return to the moon for a closer-up look in the coming decade, as NASA is developing an Artemis program to send people to the surface no earlier than 2025.

LRO will also be a valuable scout for that set of missions, as the spacecraft’s maps will be used to develop plans for lunar bases or to help scout safe landing sites for astronauts.

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