Universe Today

October 24, 2013March 16, 2017 by Fraser Cain

How Many Satellites are in Space?

The space age began on October 4, 1957 with the launch of the first artificial satellite, Sputnik 1. This tiny spacecraft lasted only three months in orbit, finally burning up in the Earth’s atmosphere.

Following in these historic footsteps, many more spacecraft have been sent into Earth’s orbit, around the Moon, the Sun, the other planets, and even out of the Solar System itself. At the time that I’m recording this video, there are 1071 operational satellites in orbit around the Earth. 50 percent of which were launched by the United States.

Half of that 1071 are in Low-Earth Orbit, just a few hundred kilometers above the surface. Some of the most notable of these include the International Space Station, the Hubble Space Telescope, and many Earth observation satellites.

About a twentieth are in Medium-Earth Orbit, around 20,000 kilometers up, which are generally global positioning satellites used for navigation. A small handful are in elliptical orbits, where their orbit brings them closer and further to the Earth.
The rest are in geostationary orbit, at an altitude of almost 36,000 kilometers.

If we could see these satellites from Earth’s surface, they would appear to hang motionless in the sky. The fact that they remain over the geographic same area means they provide the perfect platform for telecommunications, broadcast or weather observations.

But there are many, many more artificial objects orbiting the Earth. In this collection of space debris we’re talking spent boosters, dead satellites, and even misplaced gloves. According to the United States Space Surveillance Network, there are more than 21,000 objects larger than 10 cm orbiting the Earth. Just a small fraction of these are operational satellites. It’s estimated there are a further 500,000 bits and pieces between 1 and 10 cm in size.

Near Earth orbit is so polluted with junk that the International Space Station is often moved to avoid impact with dangerous chunks of space debris. Many of these objects are created through collisions, and some scientists are worried that future space travel might be too risky if we get too much junk orbiting the planet. We might seal ourselves inside a shield of shrieking metal moving at 29,000 km/hour.

Looking outwards from our own orbit, at any time there are a handful of satellites orbiting the Moon. Right now, NASA’s Lunar Reconnaissance Orbiter and Lunar Atmosphere and Dust Environment Explorer are in lunar orbit. Further still, there’s 1 spacecraft around Mercury, 1 at Venus, 3 visiting Mars and 1 orbiting Saturn. There’s a handful of spacecraft orbiting the Sun, although they’re leading or trailing the Earth in its orbit. And a few spacecraft are on trajectories to take them out of the Solar System entirely. NASA’s Voyager spacecraft, exited the Sun’s heliosphere in 2013, and entered the interstellar medium.

Starting with Sputnik’s lonely journey over 50 years ago, It’s amazing to consider just how many satellites we’ve already launched into space in just a few decades. With more launches all the time, space is becoming a busy place, with so many exciting missions to look forward to.

We have written many articles about satellites for Universe Today. Here’s an article about two satellites that collided in Earth orbit, and here are some pictures of satellites.

You can learn more about the US Space Surveillance Network from the United States Strategic Command website.

We have also recorded a whole episode of Astronomy Cast about space junk. Listen here, Episode 82: Space Junk.

October 24, 2013December 23, 2015 by Ken Kremer

NASA’s Resilient Opportunity Rover Starts Martian Mountaineering

Opportunity starts Martian Mountaineering
NASA’s Opportunity rover captured this southward uphill panoramic mosaic on Oct. 21, 2013 (Sol 3463) after beginning to ascend the northwestern slope of “Solander Point” on the western rim of Endeavour Crater – her 1st mountain climbing adventure. The northward-facing slope will tilt the rover’s solar panels toward the sun in the southern-hemisphere winter sky, providing an important energy advantage for continuing mobile operations through the upcoming winter. Assembled from Sol 3463 navcam raw images by Marco Di Lorenzo and Ken Kremer.
Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer
Story and imagery updated[/caption]

NASA’s super resilient Opportunity robot has begun a new phase in her life on the Red Planet – Martian Mountaineer!

“This is our first real Martian mountaineering with Opportunity,” said the principal investigator for the rover, Steve Squyres of Cornell University, Ithaca, N.Y.

And it happened right in the middle of the utterly chaotic US government shutdown ! – that seriously harmed some US science endeavors. And at a spot destined to become a science bonanza in the months and years ahead – so long as she stays alive to explore ever more new frontiers.

On Oct. 8, mission controllers on Earth directed the nearly decade old robot to start the ascent of Solander Point – the northern tip of the tallest hill she has encountered after nearly 10 Earth years on Mars.

Opportunity starts scaling Solander Point - her1st mountain climbing goal. See the tilted terrain and rover tracks in this mosaic view from Solander Point peering across the vast expanse of huge Endeavour Crater. Opportunity will ascend the mountain looking for clues indicative of a Martian habitable environment. This navcam camera mosaic was assembled from raw images taken on Sol 3431 (Sept.18, 2013). Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com). See the complete panoramic view below — Opportunity starts scaling Solander Point – her1st mountain climbing goal. See the tilted terrain and rover tracks in this mosaic view from Solander Point peering across the vast expanse of huge Endeavour Crater. Opportunity will ascend the mountain looking for clues indicative of a Martian habitable environment. This navcam camera mosaic was assembled from raw images taken on Sol 3431 (Sept.18, 2013). Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com). See the complete panoramic view below

The northward-facing slopes at Solander also afford another major advantage. They will tilt the rover’s solar panels toward the sun in the southern-hemisphere winter sky, providing an important energy boost enabling continued mobile operations through the upcoming frigidly harsh winter- her 6th since landing in 2004.

Opportunity will first explore outcrops on the northwestern slopes of Solander Point in search of the chemical ingredients required to sustain life before gradually climbing further uphill to investigate intriguing deposits distributed amongst its stratographic layers.

The rover will initially focus on outcrops located in the lower 20 feet (6 meters) above the surrounding plains on slopes as steep as 15 to 20 degrees.

Opportunity starts scaling Solander Point - her 1st mountain climbing goal. See the tilted terrain and rover tracks in this panoramic view from Solander Point peering across the vast expanse of huge Endeavour Crater. Opportunity will ascend the mountain looking for clues indicative of a Martian habitable environment. This navcam camera mosaic was assembled from raw images taken on Sol 3431 (Sept.18, 2013). Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com). — Opportunity starts scaling Solander Point – her 1st mountain climbing goal. See the tilted terrain and rover tracks in this panoramic view from Solander Point peering across the vast expanse of huge Endeavour Crater. Opportunity will ascend the mountain looking for clues indicative of a Martian habitable environment. This navcam camera mosaic was assembled from raw images taken on Sol 3431 (Sept.18, 2013). Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com).

At some later time, Opportunity may ascend Solander farther upward, which peaks about 130 feet (40 meters) above the crater plains.

“We expect we will reach some of the oldest rocks we have seen with this rover — a glimpse back into the ancient past of Mars,” says Squyres.

NASA’s powerful Mars Reconnaissance Orbiter (MRO) circling overhead recently succeeded in identifying clay-bearing rocks during new high resolution survey scans of Solander Point!

As I reported previously, the specially collected high resolution observations by the orbiters Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) were collected in August and being analyzed by the science team. They will be used to direct Opportunity to the most productive targets of interest

“CRISM data were collected,” Ray Arvidson told Universe Today. Arvidson is the mission’s deputy principal scientific investigator from Washington University in St. Louis, Mo.

“They show really interesting spectral features in the [Solander Point] rim materials.”

NASA’s Opportunity rover captured this southward uphill view on Oct. 21, 2013 after beginning to ascend the northwestern slope of "Solander Point" on the western rim of Endeavour Crater. The northward-facing slope will tilt the rover's solar panels toward the sun in the southern-hemisphere winter sky, providing an important energy advantage for continuing mobile operations through the upcoming winter. Credit: NASA/JPL — NASA’s Opportunity rover captured this southward uphill view on Oct. 21, 2013 after beginning to ascend the northwestern slope of “Solander Point” on the western rim of Endeavour Crater. The northward-facing slope will tilt the rover’s solar panels toward the sun in the southern-hemisphere winter sky, providing an important energy advantage for continuing mobile operations through the upcoming winter. Credit: NASA/JPL

The new CRISM survey from Mars orbit yielded mineral maps which vastly improves the spectral resolution – from 18 meters per pixel down to 5 meters per pixel.

This past spring and summer, Opportunity drove several months from the Cape York rim segment to Solander Point.

“At Cape York, we found fantastic things,” Squyres said. “Gypsum veins, clay-rich terrain, the spherules we call newberries. We know there are even larger exposures of clay-rich materials where we’re headed. They might look like what we found at Cape York or they might be completely different.”

The summit of Solander Point. Opportunity rover captured mosaic on Oct. 21, 2013 (Sol 3463) after beginning to ascend the northwestern slope of "Solander Point" on the western rim of Endeavour Crater - her 1st mountain climbing adventure. Assembled from Sol 3463 pancam high resolution raw images by Marco Di Lorenzo and Ken Kremer. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer — The summit of Solander Point
Opportunity rover captured mosaic on Oct. 21, 2013 (Sol 3463) after beginning to ascend the northwestern slope of “Solander Point” on the western rim of Endeavour Crater – her 1st mountain climbing adventure. Assembled from Sol 3463 pancam high resolution raw images by Marco Di Lorenzo and Ken Kremer. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer

Clay minerals, or phyllosilicates, form in neutral water that is more conducive to life.

At the base of Solander, the six wheeled rover discovered a transition zone between a sulfate-rich geological formation and an older formation. Sulfate-rich rocks form in a wet environment that was very acidic and less favorable to life.

Solander Point is located at the western rim of the vast expanse of Endeavour crater – some 22 kilometers (14 miles) in diameter.

Today marks Opportunity’s 3466th Sol or Martian Day roving Mars – for what was expected to be only a 90 Sol mission.

So far she has snapped over 185,200 amazing images on the first overland expedition across the Red Planet.

Her total odometry stands at over 23.89 miles (38.45 kilometers) since touchdown on Jan. 24, 2004 at Meridiani Planum.

Meanwhile, NASA is in the final stages of processing of MAVEN, the agencies next orbiter.

It is still scheduled to blast off from Cape Canaveral on Nov.18 – see my photos from inside the clean room at the Kennedy Space Center.

MAVEN’s launch was briefly threatened by the government shutdown.

On the opposite side of Mars, Opportunity’s younger sister rover Curiosity is trekking towards gigantic Mount Sharp and recently discovered a patch of pebbles formed by flowing liquid water.

Ken Kremer

Traverse Map for NASA’s Opportunity rover from 2004 to 2013. This map shows the entire path the rover has driven during nearly 10 years and over 3460 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location ascending her 1st Martian Mountain - Solander Point - at the western rim of Endeavour Crater. Opportunity discovered clay minerals at Esperance - indicative of a habitable zone and seeks clay minerals now at Solander. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer — Traverse Map for NASA’s Opportunity rover from 2004 to 2013
This map shows the entire path the rover has driven during nearly 10 years and over 3460 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location ascending her 1st Martian Mountain – Solander Point – at the western rim of Endeavour Crater. Opportunity discovered clay minerals at Esperance – indicative of a habitable zone and seeks clay minerals now at Solander. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer

October 23, 2013April 4, 2016 by Jason Major

Titan’s North Pole is Loaded With Lakes

Titan's north pole is home to many methane lakes. Credit: NASA

A combination of exceptionally clear weather, the steady approach of northern summer, and a poleward orbital path has given Cassini — and Cassini scientists — unprecedented views of countless lakes scattered across Titan’s north polar region. In the near-infrared mosaic above they can be seen as dark splotches and speckles scattered around the moon’s north pole. Previously observed mainly via radar, these are the best visual and infrared wavelength images ever obtained of Titan’s northern “land o’ lakes!”

Titan is currently the only other world besides Earth known to have stable bodies of liquid on its surface, but unlike Earth, Titan’s lakes aren’t filled with water — instead they’re full of liquid methane and ethane, organic compounds which are gases on Earth but liquids in Titan’s incredibly chilly -290º F (-180º C) environment.

While one large lake and a few smaller ones have been previously identified at Titan’s south pole, curiously almost all of Titan’s lakes appear near the moon’s north pole.

Infrared observations of Titan's northern lakes (NASA/JPL-Caltech/SSI) — Infrared observations of Titan’s northern lakes. The cross marks Titan’s geographic north pole. (NASA/JPL-Caltech/SSI)

For an idea of scale, the large lake at the upper right above (and the largest lake on Titan) Kraken Mare is comparative in size to the Caspian Sea and Lake Superior combined. Kraken Mare is so large that sunlight was seen reflecting off its surface in 2009. Punga Mare, nearest Titan’s pole, is 240 miles (386 km) across.

Besides revealing the (uncannily) smooth surfaces of lakes — which appear dark in near-infrared wavelengths but would also be darker than the surrounding landscape in visible light — these Cassini images also show an unusually bright terrain surrounding them. Since the majority of Titan’s lakes are found within this bright region it’s thought that there could be a geologic correlation; is this Titan’s version of karst terrain, like what’s found in the southeastern U.S. and New Mexico? Could these lakes be merely the visible surfaces of a vast underground hydrocarbon aquifer? Or are they shallow pools filling depressions in an ancient lava flow?

Annotated infrared mosaic of Titan's north pole (NASA/JPL-Caltech/SSI) — Annotated infrared mosaic of Titan’s north pole (NASA/JPL-Caltech/SSI)

Or, are they the remains of once-larger lakes and seas which have since evaporated? The orange-hued regions in the false-color mosaic may be evaporite — the Titan equivalent of salt flats on Earth. The evaporated material is thought to be organic chemicals originally from Titan’s haze particles that were once dissolved in liquid methane.

“Is this an indication that with increased warmth, the seas and lakes are starting to evaporate, leaving behind a deposit of organic material,” wrote Carolyn Porco, Cassini Imaging Team Leader, in an email earlier today. “…in other words, the Titan equivalent of a salt-flat?”

The largest lake at Titan’s south pole, Ontario Lacus, has been previously compared to such an ephemeral lake in Namibia called the Etosha Pan. (Read more here.)

These observations are only possible because of the extended and long-term study of Saturn and its family of moons by the Cassini spacecraft, which began with its establishing orbit in 2004 and has since continued across multiple seasons over a third of the ringed planet’s year. The existence of methane lakes on Titan is undoubtedly fascinating, but how deep the lakes are, where they came from and how they behave in Titan’s environment have yet to be discovered. Luckily, the changing season is on our side.

“Titan’s northern lakes region is one of the most Earth-like and intriguing in the solar system,” said Linda Spilker, Cassini project scientist, based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We know lakes here change with the seasons, and Cassini’s long mission at Saturn gives us the opportunity to watch the seasons change at Titan, too. Now that the sun is shining in the north and we have these wonderful views, we can begin to compare the different data sets and tease out what Titan’s lakes are doing near the north pole.”

The images shown above were obtained by Cassini’s visual and infrared mapping spectrometer (VIMS) during a close flyby of Titan on Sept. 12, 2013.

Read more on the Cassini Imaging Central Laboratory for Operations (CICLOPS) site here and on the NASA site here.

“But how thrilling it is to still be uncovering new territory on this fascinating moon… a place that, until Cassini’s arrival at Saturn nearly 10 years ago, was the largest single expanse of unseen terrain we had remaining in our solar system. Our adventures here have been the very essence of exploration. And it’s not over yet!”

– Carolyn Porco on Facebook

An illustration of a Titanic lake by Ron Miller. All rights reserved. Used with permission. — An illustration of a Titanic lake © Ron Miller. All rights reserved.

Also, check out a corresponding article and intriguing illustration of robotic Titan exploration by space artist extraordinaire Ron Miller on io9.com.

October 23, 2013December 23, 2015 by Matthew Francis

Taking Measure: A ‘New’ Most Distant Galaxy

Galaxy z8_GND_5296 (seen in the inset) is the earliest galaxy that astronomers have measured the distance to accurately. It formed approximately 700 million years after the Big Bang, and is forming stars at an incredibly rapid rate. [Credit: V. Tilvi (Texas A&M), S. Finkelstein (UT Austin), the CANDELS team, and HST/NASA]

“The farthest galaxy yet seen!” Haven’t we heard that one before? (See here and here, for example.) While it’s true that astronomers keep pushing farther back in time with better instruments, there are fundamental challenges both in observing and measuring the distances to the earliest galaxies in the cosmos.

That’s why this new observation of a galaxy that formed about 700 million years after the Big Bang is significant. While scores of galaxies have been identified that formed in that era, astronomers have only measured accurate distances for five of them. This galaxy marks the sixth, and it is the farthest of the bunch. Perhaps even more important than the distance measurement, researchers determined that this galaxy gave birth to new stars at more than 100 times the rate the Milky Way does today. That indicates early galaxies may have been more aggressive with star-formation than previously believed. Continue reading “Taking Measure: A ‘New’ Most Distant Galaxy”

October 23, 2013April 26, 2016 by Elizabeth Howell

Incredible Vertical-Landing Grasshopper Rocket Has Retired

The SpaceX Grasshopper during its test flight on March 7, 2013. Credit: SpaceX.

Did you take a moment to look at that August video of the Grasshopper rocket deliberately going sideways and then appearing to hover for a bit before returning to Earth? For more video fodder, there’s also this high-flying test the rocket took in October.

We hope you enjoyed these views, because Grasshopper is being retired. SpaceX now wants to focus its energy and resources on to the larger Falcon 9-R first stage, which should see its first test flight in New Mexico this December.

It sounds like SpaceX would have loved to go further, in a sense. “In some ways we’ve kind of failed on the Grasshopper program because we haven’t pushed it to its limit,” SpaceX president Gwynne Shotwell said at the International Symposium for Personal and Commercial Spaceflight (ISPCS) in New Mexico last week, as reported in the NewSpace Journal. “We haven’t broken it.”

Grasshopper took eight test flights during its flight history, which spanned about a year between September 2012 and October 2013. It was intended to test Vertical Takeoff Vertical Landing technology (VTVL). The strange appearance of a rocket leaving Earth and gently, deliberately touching back down again turned heads — even in the general public.

We have coverage — and videos! — of most of its past test flights here (the dates below are flight dates, not publication dates)

November 1, 2012: Flight to 106 feet (32 meters).
December 17, 2012: Flight to 131 feet (40 meters).
March 7, 2013: Flight to 262.8 feet (80.1 meters).
April 17, 2013: Flight to 820 feet (250 meters).
August 13, 2013: Divert maneuver!
October 13, 2013: Highest test flight yet (2,440 feet or 744 meters).

Most rockets are single-use only and are discarded either in orbit or (better yet, for space debris concerns) are put in a path to burn up in Earth’s atmosphere. SpaceX, however, wants its next-generation Falcon 9 rocket to have a reusable first stage to cut down on launch costs. (Grasshopper was about 10 storeys high, while the Falcon 9 will be about 14 storeys tall when carrying a Dragon spacecraft on board.)

The Falcon 9-R during a 10-second test in June 2013. Credit: Elon Musk on Twitter

As for the Falcon 9 series, a rocket flight in September delivered its payload (which included the Canadian Cassiope satellite) to space successfully, but faced some technical problems with the upper stage — and the first stage, as the rocket was supposed to be slowed down for splashdown.

As Space News reported, two burns were planned. The first worked, but the second burn took place while the rocket was spinning, which affected the flow of fuel. A picture shown by SpaceX demonstrated the rocket was intact three meters above the ocean, although it did not survive after it hit.

“Between the flights we’ve been doing with Grasshopper and this demonstration that we brought that stage back, we’re really close to full and rapid reuse of stages,” Shotwell said in the report.

October 23, 2013December 23, 2015 by Nancy Atkinson

Astrophoto: Seeing the Cygnus Capsule Before Its Demise

The orbital paths of the International Space Station and the Cygnus capsule overlap in this 20 second exposure taken from Bannister Green, England on October 22, 2013. Credit and copyright: Wendy Clark.

Here’s a nice photo of the trails in the sky from the International Space Station and Orbital Science’s Cygnus freighter. This was captured just a few hours after Cygnus was undocked from the station on October 22, 2013. Astrophotographer Wendy Clark says to “please ignore my garden spaceship to the right,” but sorry, having a model of the starship Enterprise in your yard is just too wonderful to ignore!

This is a 20 sec exposure at ISO 1600 f4.5, 18mm, taken at 19.25 BST. The brightened spot is a flare (sun-glint) from one of the spacecraft.

And about an hour ago from this posting, Orbital Sciences confirmed that the Cygnus had deorbited:

We have lost the signal from #Cygnus. Reentry accomplished. Represents the official completion of our COTS program with @NASA partners

— Orbital Sciences (@OrbitalSciences) October 23, 2013

Cygnus’ mission elapsed time (launch through deorbit) was 35 days 3 hours 18 minutes 27 seconds

Here’s another great photo of the two spacecraft together in the sky from Germany by Wolfgang Dzieran:

The International Space Station and the Cygnus capsule on October 22, 2013, as seen from from Bad Lippspringe, Eastwestphalia, Germany. Credit and copyright: Wolfgang Dzieran.

He explains what you are seeing in the photo: “The long, light line is the track in the middle is the ISS. The second track, which runs almost parallel to the orbit of the ISS is the Cygnus supply module, and at one point becomes conspicuously bright. This bright illumination is called a flare,” Dzieran writes on his website. “At top right and bottom you can see the traces of two aircraft.

Thanks to both astrophotographers for sharing their images!

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

October 23, 2013December 23, 2015 by Elizabeth Howell

What New Horizons Sounds Like (Sort Of) When It Phones Home

Now that’s a tune for a space geek’s ears. This is a highly modified sound bite of ranging signals between the Pluto-bound New Horizons spacecraft with NASA’s Deep Space Network (DSN) receiving stations.

What are the changes? The frequency has been altered to something that human ears can hear, explained a scientist in a New Horizons blog post this week:

“The ranging technique is just like seeing how much time it takes to hear the echo of your voice reflected off some object to measure how far away you are,” stated Chris DeBoy, New Horizons telecommunications system lead engineer who is with the Johns Hopkins Applied Physics Laboratory.

The ranging code first emanated from the DSN, which sent it to New Horizons. The spacecraft demodulated (or processed) the signal and sent it back to Earth. The DSN then calculated the delay (in seconds) between when it sent the signal, and when the answer was received.

“The DSN’s ‘voice’ is a million or more times higher in frequency than your voice, travels almost a million times faster than the speed of sound, and the round-trip distance is more than four billion miles,” DeBoy added.

In this case, the signals were sent June 29, 2012 from a DSN station in Goldstone, California. The answer arrived at a fellow DSN station in Canberra, Australia and yielded a round trip time of six hours, 14 minutes and 29 seconds.

Despite its great distance away, New Horizons is still almost two years from its brief encounter with Pluto and its moons in July 2015. Some interesting trivia about the mission: some Plutonian moons were discovered while the spacecraft was en route. Shows how quickly science changes in a few years.

Source: Johns Hopkins Applied Physics Laboratory

October 23, 2013December 23, 2015 by David Dickinson

Comet LINEAR Suddenly Brightens with Outburst: How to See It

Comet C/2012 X1 LINEAR as imaged by Howes, Guido & Nicolini on Monday, October 21st. (Credit: remanzacco.blogspot)

It’s swiftly becoming an “all comets, all the time” sort of observing season. The cyber-ink was barely dry on our “How to Spot Comet 2P/Encke” post this past Monday when we were alerted to another comet that is currently in the midst of a bright outburst.

That comet is C/2012 X1 LINEAR. Discovered on December 8^th, 2012 by the ongoing Lincoln Near Earth Asteroid Research (LINEAR) survey based in Socorro, New Mexico, Comet X1 LINEAR was expected to peak out at about +12^th magnitude in early 2014.

That all changed early this week, when amateur observers began to report a swift change in brightness for the otherwise nondescript comet. Japanese observer Hidetaka Sato reported the comet at magnitude +8.5 on October 20^th, a full 5.5 magnitudes above its expected brightness of +14. Remember, the magnitude scale is logarithmic, and the lower the number, the brighter the object. Also, 5 magnitudes represent an increase in brightness of 100-fold.

Astronomers Nick Howes, Martino Nicolini and Ernesto Guido used the remote 0.5 metre iTelescope based in New Mexico on the morning of Monday, October 21^st to confirm the outburst. Other amateurs and professional instruments are just now getting a look at the “new and improved” Comet X1 LINEAR low in the dawn sky. Romanian amateur observer Maximilian Teodorescu noted on yesterday’s Spaceweather that the comet was not visible through his 4.5 inch refractor, though it was easy enough to image.

Comet X1 LINEAR currently sits in the constellation Coma Berenices about mid-way between the stars Diadem, (Alpha Coma Berenices) and Beta Coma Berenices. Shining at +8.5 magnitude, the coma is about 85” across with a 10” bright central region. This gives X1 LINEAR the appearance of an unresolved +8^th magnitude globular cluster. In fact, a classic globular and a star party fave known as M3 lies about 8 degrees away at the junction of the constellations Canes Venatici, Boötes and Coma Berenices. M3 shines at +7^th magnitude and will make a great contrast on the hunt for the comet.

Unfortunately, the window of time to search for the comet is currently short. From latitude 30 degrees north, the comet sits only 15 degrees about the northeast horizon 30 minutes before local sunrise. The situation is a bit better for observers farther to the north, and mid-November sees the comet 20 degrees above the horizon in the dawn sky.

Comet X1 LINEAR is currently covering 40’ (2/3^rdsof a degree, or 1 1/3 the size of a Full Moon) a day, and will spend most of the month of November in the constellation Boötes. Keep in mind, X1 LINEAR is currently still on brightening trend “with a bullet.” Revised light curves now show it on track to reach magnitude +6 near perihelion early next year, but further brightening could still be in the cards for this one. Remember Comet 17P/Holmes a few years back? That one jumped from an uber-faint +17^th magnitude to a naked eye brightness of +2.8 in less than 48 hours.

Comet X1 LINEAR will reach a perihelion of 1.6 Astronomical Units (A.U.s) from the Sun on February 21st, 2014, and pass 1.6 A.U.s from the Earth around June 28^th, 2014. The comet has a high inclination of 44.4° degrees relative to the ecliptic, and is on a respectable 1872 year orbit.

Here are some notable dates for the comet through the end of 2013;

The path of Comet C/2012 X1 LINEAR from October 23 to November 28th. Click to enlarge. (Credit: Created using Starry Night Education Software).

-November 2^nd: Crosses into the constellation Boötes.

-November 6^th: Passes near the +4.9^th magnitude star 6 Boötis.

-November 16^th: Passes near the bright star Arcturus.

-December 6^th: Crosses into the constellation Serpens Caput.

-December 10^th: Passes near the +5 magnitude star Tau1 Serpentis.

-December 14^th: Comet X1 LINEAR sits only 8 degrees from Comet ISON.

-December 26^th: Crosses into the constellation Hercules.

Note: “Passes near” on the above list denotes a pass closer than one degree, except as noted.

Now, we REALLY need the Moon to pass Last Quarter phase this coming Saturday so we can get a good look at all of these dawn comets! As of writing this, the current scorecard of binocular comets— comets with a brightness between magnitude +6 and +10 —sits at:

-2P Encke: +7.9 magnitude in Leo.

-C/2013 R1 Lovejoy: +8.7^th magnitude in Canis Minor.

-C/2013 X1 LINEAR: +8.5^th magnitude in Coma Berenices.

-C/2012 S1 ISON: +9.7^th magnitude in Leo.

-C/2012 V2 LINEAR: +8.9^th magnitude in Centaurus.

Comet X1 LINEAR on the morning of October 25th, as seen from latitude 30 degrees north 45 minutes prior to sunrise. (Created using Stellarium).

It’s also amusing to note how the method of notification for these sorts of outbursts has changed in recent years. I first heard of the outburst of X1 LINEAR on Monday evening via Twitter. Contrast this with Comet Holmes in 2007, which came to our attention via message board RSS feed. And way back in 1983, we all read about of the close passage of Comet IRAS-Araki-Alcock… weeks after it occurred!

Another curious phenomenon may also work its way through the news cycle. When Comet Holmes became a hit back in 2007, spurious reports of comets brightening became fashionable. If you were to believe everything you read on the web, it suddenly seemed like every comet was undergoing an outburst! This sort of psychological trend towards wish fulfillment may come to pass again as interest in comet outbursts mounts.

It’s also worth noting that, contrary to rumors flying around ye’ ole web, Comet X1 LINEAR is not following Comet ISON. The two are on vastly different orbits, and only roughly lie along the same line of sight as seen from our Earthly vantage point.

The orbital path of Comet X1 LINEAR. (Credit: The JPL Solar System Dynamics Small-Body Database Browser). — The orbital path of Comet C/2012 X1 LINEAR. (Credit: The JPL Solar System Dynamics Small-Body Database Browser).

And that’s it for our weekly (daily?) segment of “As the Comets Turn…” don’t forget to “fall back” one hour and plan your morning comet-hunting vigil accordingly this coming Sunday if you live in Europe-UK. North America still has until November 3^rd to follow suit.

Happy comet hunting!

-Got a recent pic of Comet X1 LINEAR? be sure to post it in the Universe Today Flickr forum!

October 23, 2013December 23, 2015 by Jason Major

There Are Now Officially Over 1,000 Confirmed Exoplanets!

More than 1,000 exoplanets have been confirmed and cataloged (PHL @ UPR Arecibo)

It was just last week that we reported on the oh-so-close approach to 1,000 confirmed exoplanets discovered thus far, and now it’s official: the Extrasolar Planets Encyclopedia now includes more than 1,000! (1,010, to be exact.)

21 years after the first planets beyond our own Solar System were even confirmed to exist, it’s quite a milestone!

The milestone of 1,000 confirmed exoplanets was surpassed on October 22, 2013 after twenty-one years of discoveries. The long-established and well-known Extrasolar Planets Encyclopedia now lists 1,010 confirmed exoplanets.

Not all current exoplanet catalogs list the same numbers as this depends on their particular criteria. For example, the more recent NASA Exoplanet Archive lists just 919. Nevertheless, over 3,500 exoplanet candidates are waiting for confirmation.

The first confirmed exoplanets were discovered by the Arecibo Observatory in 1992. Two small planets were found around the remnants of a supernova explosion known as a pulsar. They were the surviving cores of former planets or newly formed bodies from the ashes of a dead star. This was followed by the discovery of exoplanets around sun-like stars in 1995 and the beginning of a new era of exoplanet hunting.

A "Periodic Table of Exoplanets" as listed by the Extrasolar Planets Encyclopedia (PHL) — A “Periodic Table of Exoplanets” as listed by the Extrasolar Planets Encyclopedia (PHL)

(The first exoplanets to be confirmed were two orbiting pulsar PSR B1257+12, 1,000 light-years away. A third was found in 2007.)

Exoplanet discoveries have been full of surprises from the outset. Nobody expected exoplanets around the remnants of a dead star (i.e. PSR 1257+12), nor Jupiter-size orbiting close to their stars (i.e. 51 Pegasi). We also know today of stellar systems packed with exoplanets (i.e. Kepler-11), around binary stars (i.e. Kepler-16), and with many potentially habitable exoplanets (i.e. Gliese 667C).

“The discovery of many worlds around others stars is a great achievement of science and technology. The work of scientists and engineers from many countries were necessary to achieve this difficult milestone. However, one thousand exoplanets in two decades is still a small fraction of those expected from the billions of stars in our galaxy. The next big goal is to better understand their properties, while detecting many new ones.”

– Prof. Abel Mendéz, Associate Professor of Physics and Astrobiology, UPR Arecibo

Source: Press release by Professor Abel Méndez at the Planetary Habitability Laboratory (PHL) at Arecibo

While not illustrating the full 1,010 lineup, this is still a mesmerizing visualization by Daniel Fabrycky of 885 planetary candidates in 361 systems as found by the Kepler mission. (I for one am looking forward to the third installment!)

Of course, scientists are still hunting for the “Holy Grail” of extrasolar planets: an Earth-sized, rocky world orbiting a Sun-like star within its habitable zone. But with new discoveries and confirmations happening almost every week, it’s now only a matter of time. Read more in this recent article by Universe Today writer David Dickinson.

October 23, 2013April 26, 2016 by Elizabeth Howell

Proposed Balloon Ride Would Let You See The Blackness Of Space

Artist's conception of World View's planned balloon mission some 19 miles (30 kilometers) up. Credit: World View Enterprises Inc.

Doesn’t that look fun? A startup company is proposing to send customers 19 miles (30 kilometers) into the air via balloon, where they can linger for two hours and look at the curvature of the Earth and experience a black sky. While it’s not high enough to qualify as a spaceflight, the listed ticket price may be a little more affordable for space enthusiasts: $75,000.

Don’t get too excited yet — the project appears to be in very early stages, and no “first flight” date is listed yet. But there are some interesting notes for those looking for space and science experience in the company.

Among the members of its executive is Alan Stern, the principal investigator for the New Horizons Pluto mission and NASA’s former associate administrator for the science mission directorate. (He’s also the CEO of the Golden Spike company that wants to offer commercial human missions to the moon.)
The executive also includes Jane Poynter and Taber MacCallum, who were both members of Biosphere 2. More recently, they also took on senior positions in Inspiration Mars, a Dennis Tito-led project that aims to send humans past Mars. (The target launch date for that is Jan. 5, 2018.)
The company proposing to build it is Paragon Space Development Corp. (which Poynter and MacCallum co-founded.) Paragon’s customers for thermal, environment and life support systems include a lot of name brands (including NASA). Paragon is also doing work for the Inspiration Mars project as well as Mars One, which aims to send colonists on a one-way trip to the Red Planet by 2023.

Artist's conception of World View's passenger capsule that will be carried aloft during a proposed balloon flight. Credit: World View Enterprises Inc. — Artist’s conception of World View’s passenger capsule that will be carried aloft during a proposed balloon flight. Credit: World View Enterprises Inc.

“Seeing the Earth hanging in the ink-black void of space will help people realize our connection to our home planet and to the universe around us, and will surely offer a transformative experience to our customers,” stated Poynter, who is CEO of World View. “It is also our goal to open up a whole new realm for exercising human curiosity, scientific research and education.”

World View’s announcement came after the Federal Aviation Administration “determined that World View’s spacecraft and its operations fall under the jurisdiction of the office of Commercial Space Flight,” the company added.

More information on their mission is available on the World View website. It’s a bit of a different track than Virgin Galactic and XCOR, who are offering rides into suborbital space for prices of $250,000 and $95,000, respectively. Neither company has an operational spacecraft yet, but they are in flight testing. Reports indicate they are hoping to get flights going next year.