Universe Today

October 28, 2013April 26, 2016 by David Dickinson

Rare ‘Hybrid’ Solar Eclipse on November 3, 2013: How to See It

A partially eclipsed setting Sun as seen from Dallas, Texas on May 20th, 2012. This weekend's eclipse will offer U.S. East Coast residents a similar sunrise view. (Credit: Jason Major/Lights in the Dark).

It’s almost upon us. The final eclipse of 2013 occurs this coming weekend on Sunday, November 3^rd. This will be the fifth eclipse overall, and the second solar eclipse of 2013. This will also be the only eclipse this year that features a glimpse of totality.

This eclipse is of the rare hybrid variety— that is, it will be an annular eclipse along the very first 15 seconds of its track before transitioning to a total as the Moon’s shadow sweeps just close enough to the Earth to cover the disk of the Sun along the remainder of its track.

An animation of the path of the November 3rd hybrid solar eclipse. (Credit: NASA/Goddard Space Flight Center).

How rare are hybrid solar eclipse? Of the 11,898 solar eclipses listed over a 5,000 year span from 1999 BC to 3000 AD in Fred Espenak’s Five Millennium Catalog of Solar Eclipses, only 569, or 4.8% are hybrids.

Who can see this eclipse?

People from northern South America, across the U.S. Eastern Seaboard and up through the Canadian Maritimes will see a brief partial solar eclipse finishing up around 30 minutes after local sunrise. The brief annular “ring of fire” portion of the eclipse begins at sunrise just ~1,000 kilometres east of Jacksonville, Florida, as it races eastward across the Atlantic. See our timeline, below.

Eclipse prospects for the US East Coast. (Courtesy of Michael Zeiler @EclipseMaps)

Nearly all of Africa and the southern Mediterranean region including Spain will see partial phases of the eclipse, while greatest totality occurs just off of the coast of Liberia and heads for first landfall on the African continent over Wonga Wongue Reserve in Gabon. At this point, the duration of totality will already have shrunk back down to 1 minute and 7 seconds. The shadow of the Moon will then cross central Africa, headed for a short but brilliant sunset total eclipse over Uganda, Ethiopia, Kenya and Somalia.

The global path of this weekends eclipse-click to enlarge. (Credit: Michael Zeiler, @EclipseMaps).

This particular eclipse part of saros series 143 and is member 23 of the 72 eclipses in the cycle. The first eclipse in this saros occurred on March 7^th, 1617, and the last one will occur on April 23^rd, 2897.

Saros 143 also has a checkered place in eclipse history. The last eclipse in this series crossed south eastern Asia on October 24^th, 1995.

The first detailed picture of a solar eclipse was also taken of a saros 143 member on July 28, 1851. And one saros later, a total solar eclipse on August 7^th, 1869 may have saved the butt of astronomer and explorer George Davidson while traversing the wilds of Alaska. And one more saros period later, Dmitri Mendeleev (he of the modern periodic table) observed the total solar eclipse of August 19^th, 1887 from a balloon.

A daguerreotype image of the 1851 eclipse captured by Berkowski of the Royal Observatory in Königsberg, Prussia. (Public domain image).

We’ve compiled a brief worldwide timeline for the November 3^rd hybrid eclipse. Keep in mind, the shift back off of Daylight Saving Time occurs on the same morning as the eclipse for North America, putting the U.S. East Coast once again back to -5 hours off of Universal Time (UT):

10:04 UT: The partial phases of the eclipse begin.

11:05:17 UT: annular phases of the eclipse begin.

11:05:36 UT: The eclipse transitions from an annular to a total along its track.

12:46: The point of greatest eclipse, occurring off of the SW coast of Liberia along the coast of Africa. The path will be 57 kilometres wide at this point with a maximum duration for totality at 1 minute & 40 seconds.

14:27 UT: The total phases of the eclipse end.

15:28 UT: Partial phases end.

Remember that solar safety is paramount while observing an eclipse during all partial phases. This is especially critical, as millions of viewers along the U.S. East Coast are poised to catch the eclipse at sunrise over the Atlantic on Sunday. Use only glasses designed specifically for eclipse viewing or welder’s glass #14. One project headed by Astronomers Without Borders is also working to provide eclipse glasses to schools in Africa.

Students in Tanzania demonstrating proper eclipse viewing safety. (Credit: Astronomers Without Borders).

Projecting the Sun onto a wall or a piece of paper is also a safe method to observe the eclipse. Construction of a Sun Gun, a pinhole projector, or even using a spaghetti strainer or colander to project the partially eclipsed sun are all fun projects to try.

Shooting pictures of the rising eclipse is also possible using a DSLR. To capture the disk of the Sun plus an outline of the foreground, you’ll want to use a combination of low ISO 100 and a fast shutter speed (1/4000 or faster) and a zoom lens of at least 200mm or greater. Keep in mind, DO NOT look at the Sun through the camera’s view finder— simply set the focus to infinity and aim via projection. It’s worth practicing your technique a morning or two prior to the main event!

As the partial phase of the eclipse progresses, keep an eye out for “tiny crescents” that may litter the ground. These are caused by gaps in things such as leaves, latticework, etc that may act as natural “pinhole projectors”. Those lucky enough to stand in the path of totality may snare a look at shadow bands sweeping across the landscape as totality approaches, as well as catch a brief glimpse of Baily’s Beads and the pearly white corona of the Sun.

Totality will last less than a minute across most of central Africa, giving viewers a very hurried view before partial phases commence once more. Venus will be easily visible at magnitude -4.4 just 47 degrees east of the Sun. Unfortunately, prospects aren’t great for air or seaborne viewers in the mid-Atlantic to catch sight of comet ISON during the frenzied moments of totality, which will sit 50 degrees from the Sun between magnitude +7 & +8.

The sky over Gabon during mid-eclipse. (Created by the author using Starry Nite).

Weather prospects are an all-important consideration when planning for an eclipse. Jay Anderson maintains an outstanding site with projections tailor-made for each eclipse. For the U.S. East Coast, clear skies right down to the crucial eastern horizon will be key!

A recent surge in piracy off of the West Coast of Africa may also factor into travel considerations for eclipse chasers. You can actually monitor such activities on the high seas now in near real time. Perhaps one could take a page from Mark Twain’s A Connecticut Yankee in King Arthur’s Court, and impress any would-be-brigands with the glory of an impending solar eclipse…

Unfortunately, the International Space Station will have an orbit nearly perpendicular to the Earth-Moon-Sun syzygy, and won’t lend itself to any great prospects of a transit during the partial phases of the eclipse. ESA’s Proba-2 and JAXA’s Hinode will, however, see several partial eclipses from orbit:

Sunspot activity has also been on the upswing as of late, making for a photogenic Sun heading into the partial phases of the eclipse. A well-placed, naked eye Coronal Mass Ejection on the solar limb also isn’t out of the question. Eclipse historian and expert Michael Zeiler notes that a CME last occurred during a total solar eclipse way back in 1860.

Sunspot activity as of October 28th... will it stay active until this weekend's eclipse? (Photo by author). — Sunspot activity as of October 28th… will it stay active until this weekend’s eclipse? (Photo by author).

Totality for this eclipse passes over some wild and largely wifi free areas; few plans to broadcast the eclipse live have surfaced thus far.

Slooh plans a broadcast, as did a proposed Indiegogo project whose current status is unclear. BRCK also plans to broadcast the eclipse live from the shores of Lake Turkana, Kenya. Got plans to webcast even the partial phases of the eclipse? Let us know!

And speaking of eclipse chasing, we plan on heading to the Florida Space Coast Sunday morning at o’dark thirty to nab the partial sunrise eclipse over the Atlantic.

And as always, the question posed immediately after totality is: when’s the next one? Well, the next annular eclipse graces Australia on April 29^th, 2014. The U.S. will also see a partial solar eclipse on October 23^rd next year… but totality will not touch the surface of our fair planet until a high Arctic eclipse on March 20^th, 2015.

Good luck, clear skies, and safe journeys to all who are chasing after this one near and far, and don’t forget to post those pics to Universe Today’s Flickr page!

-See more of Michael Zeiler’s work at Eclipse Maps.

-Simulations were created using Starry Night Education Software.

October 28, 2013December 28, 2015 by Fraser Cain

Astronomy Cast 319: The Zodiac

Although the Zodiac is best known for astrology nonsense, it has a purpose in astronomy too. The constellations of the Zodiac define the plane of the ecliptic: the region where the Sun, Moon and planets appear to travel through the sky. What are the constellations of the Zodiac, and how do astronomers use them as way points?

We record Astronomy Cast as a live Google+ Hangout on Air every Monday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.

October 28, 2013December 23, 2015 by Elizabeth Howell

Moonstruck: Private Moon Robot Competition Coming To A Theater Near You

Screenshot from "Back To The Moon For Good", a dome show from the Google Lunar XPRIZE. The show covers the history of lunar exploration with an emphasis on the XPRIZE teams planning to make robotic journeys there themselves. Credit: Google Lunar XPRIZE

To drum up publicity for the Google Lunar XPRIZE missions, the organization has produced a “dome film” about exploring the moon through the past to the future — and is giving away the product for free to dozens of dome theaters and planetariums worldwide.

Among Back To the Moon For Good’s first appearances will be the National Science Center at Leicester, United Kingdom on Nov. 6, and a United States premiere is on its way shortly. A full list of participating venues so far is at this website. The target audience for the show (which is designed for a wraparound theater) is elementary and secondary school students.

“It was Mercury, Gemini and Apollo that took the us into space, and ultimately to the moon, and this was incredibly exciting and was responsible for lots of folks going into science and technology over the years,” said Bob Weiss, who is XPRIZE’s president and executive producer of the film, in a Universe Today interview.

“We would like to provide a 21st century version of that, but as a new kind of space mission, more interactive and participatory,” he added, saying that social media and Internet websites would be a couple of ways people at home can stay engaged in the mission or missions to the moon. (That definitely wasn’t possible generally when Apollo 11, the first moon mission, landed in 1969!)

Screenshot from "Back To The Moon For Good", a Google Lunar XPRIZE dome movie. Credit: Google Lunar XPRIZE — Screenshot from “Back To The Moon For Good”, a Google Lunar XPRIZE dome movie. Credit: Google Lunar XPRIZE

The narrator of the show is Tim Allen, an actor best known for the Home Improvement series of the 1990s. Allen, by the way, is a fan of space himself (says Weiss) and also appeared in a 1999 parody science fiction film called Galaxy Quest. Weiss said the desire was to find somebody who was family-friendly, well-known and enthusiastic about the project.

By the way, loyal fans of Home Improvement will recall that astronauts appeared on the “Tool Time” segment of the show on several occasions, usually after Hubble Space Telescope repair missions. (NASA astronaut Ken Bowersox appeared three times himself, in 1994, 1996 and 1998.)

In Season 3 show “Reality Bytes” in 1994, Tim Allen’s character asked STS-61 commander Dick Covey what the difference was between repairs in space and repairs on Earth. “It’s actually a lot like using tools here on Earth. Except there’s no gravity, so you don’t have to worry about dropping a tool on your foot,” Covey quipped.

If “Tool Time” was taking place now, we wonder if Allen would also be interviewing private companies working on robotic and human spaceflight. XPRIZE is still chugging along well, Weiss said, and added some of the teams have signed launch contracts to send their robots to the moon. (He declined to provide many details, citing confidentiality reasons.)

NASA astronaut Story Musgrave rides the Canadarm during the Hubble Space Telescope repair mission STS-61, in 1993. Credit: NASA

“We have folks who have launch contracts to go to the moon, and another serious sign is when there is real flight hardware that is being built and tested. I have seen myself some of this hardware, and there are teams that are really racing to beat each other,” he said.

“There are approximately 20 teams around the world competing to do this. It has been an interesting competition, watching some teams drop off and some devolve and recombine with each other.”

Teams have until Dec. 31, 2015 to send a robotic spacecraft to the moon, travel 500 meters (whether on, below or above the surface), and transmit two “mooncasts” for Earth. At least $40 million in “incentive-based prizes” are up for grabs. We’ve covered a few of the concepts on Universe Today before, such as one team seeking to send robots into moon caves, and a college group trying to put a rover on the surface.

Check out more information on the teams on the Google Lunar XPRIZE website.

October 28, 2013December 23, 2015 by Katrina Cain

Giveaway and Review: Astronomy Photographer of the Year: Collection Two

Universe Today and Royal Observatory Greenwich are pleased to offer one free copy of Astronomy Photographer of the Year: Collection Two!

Universe Today Review by Dave Dehetre

Astronomy Photographer of the Year is a large format glossy book that covers the Royal Observatory, Greenwich’s annual astrophotography competition. It covers the competition years from 2009 to 2012 and subject categories: Earth and Space, Our Solar System, Deep Space, Young Astronomy Photographer, People and Space, Best Newcomer, and Robotic Scope. It also includes a brief how-to primer on astrophotography which, while fine, seemed perfunctory and tacked on.

The book is organized by years and then by category, with nice double page section breaks and clear detailed info alongside each image. However, within each year, the categories aren’t delineated, either through typographic means, such as headers or section breaks, or through any indication alongside the images themselves. Usually the category was obvious enough, but it was somewhat confusing at times. Each category contains images by the winner, runner-up, and sometimes one or more ‘highly-commended’ entrants. Some categories also had other images without any designation of why they were included. This could be a typographic omission of some sort, or it could be that they were just additional entrants worthy of inclusion.

I was happy to see the consistently high caliber of work that came out of the competition. There isn’t one image in the book that was less than outstanding. I’ve spent many a night far out in the countryside doing astrophotography as a hobby, and I’ve never come up with an image to compare.

I was also happy to see the competition segmented into subject areas as well as the more expected age/experience categories. This seems to acknowledge that there are different metrics and merit for the broad scope of styles/subjects in astrophotography.

One other point worth mentioning is that I found that many of the astrophotographers presented were people I was already familiar with, some from Flickr, some from Youtube, and some from periodicals like Sky at Night. I knew these people, and not because they produce great images, but because they are some of the people I learned astrophotography from. I think this points out one of the great underlying aspects of astrophotography: that it is collaborative in nature. And I find it heartening that the people who share the most, who help others and communicate, seem to be the ones who do the best work and are the most successful.

I’m of two minds about Astronomy Photographer of the Year though. On the one hand, it’s very well done, beautiful, and stunning. Really everything you could ask for in a book on this subject. But against it, in part it is trying to document something (astrophotography) that is bigger and richer than can be captured in a book.

While the images are flawlessly presented, they lack the backlit brilliance provided by a computer screen, and they aren’t zoomable to view fine details. Many astrophotography images are available on-line at resolutions equivalent to wall-size if they were printed out.

There is also the problem of completeness. While the book is cover-to-cover with great images, in large part it is singular images from outstanding photographers who have dozens or hundreds of stunning images on-line. I found myself flipping a few pages at a time, and then being overcome with a desire to go search out a photographer’s other images. This is perhaps an inevitable outcome of the fact that the competition was conducted on-line (via Flickr), so it’s hard to see it as a negative.

So it really is a fantastic book, I love having it on my shelf, and I often flip through at random and find myself getting inspired, but I don’t think I would have searched it out for that purpose, and I’m not sure who the target customer is supposed to be. It seems incomplete and cursory, especially in the technical details, for someone already involved with the hobby and yet it has a price tag and scope that seem inconsistent with an introductory level book. It would make a great addition to a library collection.

If you want to purchase a copy of Astronomy Photographer of the Year: Collection Two, it is available on Amazon.com.

Universe Today and Royal Observatory Greenwich are pleased to be able to offer one free copy of Astronomy Photographer of the Year: Collection Two to our readers. In order to be entered into the giveaway drawing, just put your email address into the box at the bottom of this post (where it says “Enter the Giveaway”) before Monday, November 4, 2013. If this is the first time you’re registering for a giveaway from Universe Today, you’ll receive a confirmation email immediately where you’ll need to click a link to be entered into the drawing. For those who have registered previously, you’ll receive an email later where you can enter this drawing.

October 28, 2013December 23, 2015 by Elizabeth Howell

Closest Star To Our Sun Beckons In New Hubble Image

A Hubble Space Telescope image of Proxima Centauri, the closest star to Earth. Credit: ESA/Hubble & NASA

Remember that planet discovered near Alpha Centauri almost exactly a year ago? As you may remember, it’s the closest system to Earth, making some people speculate about how quickly we could get a spacecraft in that general direction. Four light years is close in galactic terms, but it’s a little far away for the technology we have now — unless we wanted to wait a few tens thousands of years for the journey to complete.

Meanwhile, we can at least take pictures of that star system. The Hubble Space Telescope team has released a new picture of Alpha Centauri’s sister star, Proxima Centauri. While Proxima is technically the closest star to Earth, it’s too faint to be seen by the naked eye, which is not all that surprising given it is only an eighth of the sun’s mass. Sometimes, however, it gets a little brighter.

“Proxima is what is known as a ‘flare star’, meaning that convection processes within the star’s body make it prone to random and dramatic changes in brightness.” stated the Hubble European Space Agency Information Centre.

“The convection processes not only trigger brilliant bursts of starlight but, combined with other factors, mean that Proxima Centauri is in for a very long life.”

How long? Well, consider the following: the universe is about 13.8 billion years old and Proxima is expected to remain in middle age for another four TRILLION years. Plenty of time for us to send a spacecraft over there if we’re patient enough. (The universe itself is expected to last a while, as Wise Geek explains.)

The picture was nabbed with Hubble’s Wide Field and Planetary Camera 2, with neighbouring stars Alpha Centauri A and B out of the frame.

Source: Hubble European Space Agency Information Centre

October 28, 2013December 23, 2015 by Nancy Atkinson

Stunning New Flyover Video: Volcanoes, Canyons and Craters of Mars

Mars Express over water-ice crater. ESA Celebrates 10 Years since the launch of Mars Express. This artists concept shows Mars Express set against a 35 km-wide crater in the Vastitas Borealis region of Mars at approximately 70.5°N / 103°E. The crater contains a permanent patch of water-ice that likely sits upon a dune field – some of the dunes are exposed towards the top left in this image. Copyright ESA/DLR/FU-Berlin-G.Neukum

Go from the highest volcano to the deepest canyon on Mars in this great new complication video from images taken by ESA’s Mars Express. The data shown here was gathered from the nearly 12,500 orbits by the Mars Express spacecraft since its arrival at the Red Planet in late 2003, and used to create digital topographic models of almost the entire surface of the planet. Not only does this provide unique and stunning visualization to create these “flyovers” of various locals on Mars, it also enables researchers to acquire new and surprising information about the evolution of the Red Planet.

The images in this movie were taken by the High Resolution Stereo Camera and the video was released by the DLR German Aerospace Center as part of the ten years of Mars Express celebrations in June 2013, and was just released online today.

Enjoy another recent Mars Express video, a flythrough of Hebes Chasma:

October 28, 2013December 23, 2015 by Nancy Atkinson

ATV-4 ‘Einstein’ Says Goodbye to the Space Station

The current Expedition 37 crew took this picture inside the ATV-4 before undocking as a tribute to Albert Einstein. Credit: ESA/Luca Parmitano.

The Expedition 37 crew onboard the International Space Station closed the hatch and said goodbye to the ATV-4 “Albert Einstein” cargo ship early this morning, Oct. 28. Europe’s 4th Automated Transfer Vehicle undocked at 08:55 UTC (4:55 a.m. EDT). The cargo carrier was filled with trash and it will be deorbited on Nov. 2 for a destructive entry back into the Earth’s atmosphere over the Pacific Ocean. ATV-4 has been at the ISS since June 15, delivering more than 7 tons of food, fuel and supplies. Its departure helps prepare for more action at the ISS: the current Soyuz spacecraft docked at the station will be moved to a different location so that a new Soyuz can dock with three new crew members. The Soyuz TMA-11M is scheduled to launch on Nov. 6, 2013 with the Expedition 38/39 crew of Rick Mastracchio, Koichi Wakata, Mikhail Tyurin.

Some images of the undocking, below:

This photo was taken from Japan shorty after the undocking:

??(10/28)19:45~???1???????????? #ATV4 ??????????????? #ISS (?????????)? f105mm ??2.5??2???? #mysky pic.twitter.com/gnQ5ny2Gjp

— JR5EPQ”SHO” (@JR5EPQ) October 28, 2013

ATV-4 backing away from the ISS. Credit: NASA TV.

The ATV-4 is just visible as it passes into Earth's terminator. Credit: NASA TV. — The ATV-4 is just visible as it passes into Earth’s terminator. Credit: NASA TV.

October 28, 2013December 23, 2015 by Katrina Cain

Giveaway and Review: Star Trek Federation: The First 150 Years

Hello Readers! We have a new book review and giveaway for your enjoyment: Star Trek Federation: The First 150 Years.

From the Publisher:

Star Trek Federation: The First 150 Years
For the first time, an ‘in universe’ history of Star Trek, complete with excerpts from Starfleet records and intergalactic intelligence, including James T. Kirk’s official biography and newly translated Klingon reports.

Star Trek Federation: The First 150 Years celebrates the 150th anniversary of the founding of the United Federation of Planets.

This unprecedented illustrated volume chronicles the pivotal era leading up to Humankind’s First Contact with Vulcan in 2063, the Romulan War in 2156, the creation of the Federation in 2161, and the first 150 years of the intergalactic democracy up until the year 2311. Meticulously researched, this account covers a multitude of alien species, decisive battles, and the technology that made the Age of Exploration possible. It includes field sketches, illustrations, and reproductions of historic pieces of art from across the Galaxy, along with over fifty excerpts from key Federation documents and correspondence, Starfleet records, and intergalactic intelligence.

David A. Goodman has spent the last 26 years writing for television. His credits include The Golden Girls, Star Trek: Enterprise, Futurama (where he wrote the Nebula Award nominated Star Trek homage “Where No Fan Has Gone Before”), and Family Guy where he was head writer for six years. This is his first book. He lives in Pacific Palisades, CA with his family.

You can purchase a copy of Star Trek Federation: The First 150 Years through Amazon.com.

Universe Today Review by Kristopher A. Poskey

Hypothetically, in the year 2347, young students throughout the Alpha Quadrant of The United Federation of Planets have found the book Star Trek Federation, The First 150 Years an exhilarating 167 page chronological review of exploration and diplomacy in space. Yet, here we are in the year 2013, reading as if we had survived to see the end of the first 150 years.Perhaps 27 year old David A. Goodman, Memory Alpha Historian, has travelled back in time to the year 2013 and brought this book back with him.

Goodman is well known for his work on “The Golden Girls”, “Family Guy”,” Futurama”, and ultimately his work on “Star Trek: Enterprise”. Goodman first publicly expressed his interest in Star Trek when he wrote, Where No Fan Has Gone Before, a well-known Futurama episode from the fourth season dedicated to Star Trek (it was nominated for the Nebula Award). Perhaps Goodman may even speak Klingon, but this episode showed just how vast Goodman’s knowledge was of Star Trek, its characters, and its history. Goodman says the inspiration for this book came from “The Star Trek Spaceflight Chronology” that was published in December, 1979. As its title suggests, the original book chronicles humans’ space ventures from Sputnik I to the events depicted in “Star Trek: The Motion Picture”.

Goodman’s new book begins on April 5, 2063 with the events surrounding “First Contact” and extends to the year 2311. The year 2311 marked the first 150 years of The Federation. As any good historian, Goodman not only told the stories that built the federation, but included minute details, allowing the reader to get a full grasp on what kinds of dynamic situations, the early pioneers faced. Goodman teamed up with 4 artists (Joe Corroney, Mark McHaley, Cat Staggs, and Jeff Carlisle) to add a plethora of illustrations that bring the history and its stories to life. Depictions of your favorite characters and pivotal moments truly add a new perspective to this captivating story. Excerpts from the Captain’s Log, as well as newspaper clippings are scattered throughout the book. Documents written in Klingon, Vulcan, Andorian, Romulan, Tellarite, and Coridan are included, along with their English translations. These and many other surprises lie within the pages of this sophisticated historical document.

If you’re an avid Trekkie, this book is a must-have for your collection (you may even learn a thing or two). If you’ve never been a huge Star Trek fan, this book will still appeal to you, not only in an emotional but also in a logical way. While the book is particularly broad about specifics, it focuses on the Federation as a whole, and the more widespread effects of decisions the leaders made. While we may have enjoyed the detail and the excitement in each episode of Star Trek, from our younger days, this book truly takes the story to a whole new level: by evaluating the entire galaxy and plotting the historical significance of various events that occurred. This book is a must read for Star Trek and science fiction fans alike.

Universe Today and Titan Books are pleased to be able to offer two free copies of Star Trek Federation to our readers. In order to be entered into the giveaway drawing, just put your email address into the box at the bottom of this post (where it says “Enter the Giveaway”) before Monday, November 4, 2013. If this is the first time you’re registering for a giveaway, you’ll receive a confirmation email immediately where you’ll need to click a link to be entered into the drawing. For those who have registered previously, you’ll receive an email later where you can enter this drawing.

October 28, 2013March 16, 2017 by Fraser Cain

How Far is Earth from the Sun?

It’s amazing to think that for the majority of human history, we had almost no understanding about the Sun. We didn’t know what it was made of, how it formed, or how it produced energy. We didn’t know how big it was, and we didn’t know how far away it was.

We orbit the Sun at a distance of about 150 million kilometers. This number is actually an average, since we follow an elliptical path. At its closest point, the Earth gets to 147 million km, and at its most distant point, it’s 152 million km.

Distances in the Solar System are so vast that astronomers use this distance as a standard for measurement, and so the average distance from the Earth to the Sun is called an astronomical unit. Instead of saying that Pluto is 5.87 billion kilometers away from the Sun, astronomers say that it’s 39 astronomical units, or AUs.

You might be surprised to know that the distance from the Sun to the Earth was only determined within the last few hundred years. There were just too many variables. If astronomers knew how big it was, they could figure out how far away it was, or vice versa, but both of these numbers were mysteries.

Ancient astronomers, especially the Greeks, tried estimating the distance to the Sun in several different ways: measuring the length of shadows on Earth, or comparing the size of the Moon and its orbit to the Sun. Unfortunately, their estimates were off at least by a factor of 10.

The key to figuring out the distance to the Sun came from observing Venus as it passed directly in front of the Sun. This rare event, known as a Transit of Venus, happens only twice every 108 years. Once devised, the best opportunities for taking this precise measurement came during the Venus transits of 1761 and 1769. Astronomers were dispatched to remote corners of the globe to observe the precise moment when Venus began to move in front of the Sun, and when it had moved completely across the surface.

By comparing these measurements, astronomers could use geometry to calculate exactly how far away the Sun is. Their initial calculations put the distance at 24,000 times the radius of the Earth. Not bad considering our modern measurement of 23,455 times the radius of the Earth.

Modern astronomers can use radar and laser pulses to calculate the distance to objects in the Solar System. For example, they fire an intense beam of radio waves at a distant object, like Mercury, and then calculate how long it takes for the waves to bounce off the planet and return to Earth. Since the speed of light is well known, the return travel time tells you how far away the planet is.

Astronomy has truly helped us find our place in the Universe. It nice to be living in a time when many of these big mysteries have been solved. I don’t know about you, but I can’t wait to see what’s around the corner of the next discovery.

October 27, 2013December 23, 2015 by Ken Kremer

Dream Chaser spaceship test article damaged during 1st Free-Flight Drop Test

Sierra Nevada Dream Chaser engineering test article in flight during a captive-carry test this past summer. Credit: NASA

The engineering test article of the commercial Dream Chaser spaceship being developed by Sierra Nevada Corp (SNC) suffered some significant damage during its critical 1st ever approach-and-landing (ALT) drop test on Saturday, Oct. 26, in California due to an unspecified type of malfunction with the deployment of the left landing gear.

The Dream Chaser mini-shuttle suffered “an anomaly as it touched down on the Runway 22L at Edwards Air Force Base, Calif.,” according to a post-test statement from NASA.

A report at NASA Spaceflight.com indicated that the Dream Chaser “flipped over on the runway” after touchdown.

The full extent of damage to the winged vehicle or whether it can be repaired and reflown is not known at this time. No photos or details explaining the damage have yet emerged – beyond brief press releases issued by SNC and NASA.

The performance of the vehicles’ nose skid, brakes, tires and other flight systems is being tested to prove that it can safely land an astronaut crew returning from the space station after surviving the searing heat of re-entry from Earth orbit.

This initial atmospheric drop test was conducted in an automated mode. There was no pilot on board and no one was hurt on the ground.

“No personnel were injured. Damage to property is being assessed,” said NASA. “Edwards Air Force Base emergency personnel responded to scene as a precaution.

“Support personnel are preparing the vehicle for transport to a hangar.”

Dream Chaser is one of three private sector manned spaceships being developed with funding from NASA’s commercial crew program known as Commercial Crew Integrated Capability (CCiCap) initiative to develop a next-generation crew transportation vehicle.

Dream Chaser on the runway with landing gear deployed. Credit: NASA

The NASA seed money aims at restoring America’s manned spaceflight access to low Earth orbit and the International Space Station (ISS) – perhaps by 2017 – following the forced shutdown of the Space Shuttle program in 2011.

Until one of the American commercial space taxis is ready for liftoff, NASA is completely dependent on the Russian Soyuz capsule for astronaut rides to the ISS at a cost of roughly $70 million per seat.

SNC was awarded $227.5 million in the current round of NASA funding and must complete specified milestones including up to five ALT drop tests to check the aerodynamic handling.

To date this test vehicle has successfully accomplished a series of runway tow and airborne captive carry tests.

Dream Chaser commercial crew vehicle built by Sierra Nevada Corp docks at ISS

Development of crew versions of the SpaceX Dragon and Boeing CST-100 capsules are also being funded by NASA’s commercial crew program office.

Dream Chaser can carry a crew of up to seven and is the only reusable, lifting body shuttle type vehicle with runway landing capability among the three competitors.

Scale models of NASA’s Commercial Crew program vehicles and launchers; Boeing CST-100, Sierra Nevada Dream Chaser, SpaceX Dragon. Credit: Ken Kremer/kenkremer.com — Scale models of NASA’s Commercial Crew program vehicles and launchers; Boeing CST-100, Sierra Nevada Dream Chaser, SpaceX Dragon.
Credit: Ken Kremer/kenkremer.com

During Saturday’s test, SNC was performing the first in a series of free-flight approach-and-landing tests with the Dream Chaser prototype test vehicle known as the ETA.

The prototype spaceship was released as planned from its carrier aircraft, an Erickson Air-Crane helicopter, at approximately 11:10 a.m. Pacific Standard Time (2:10 p.m. EDT), said SNC in a statement.

Dream Chaser awaits launch atop United Launch Alliance Atlas V rocket

The post release flare and touchdown appeared normal at first until the left landing gear deployment failed at some point after runway touchdown.

“Following release, the Dream Chaser spacecraft automated flight control system gently steered the vehicle to its intended glide slope. The vehicle adhered to the design flight trajectory throughout the flight profile. Less than a minute later, Dream Chaser smoothly flared and touched down on Edwards Air Force Base’s Runway 22L right on centerline,” according to the SNC press release.

SNC went on to say that reviews are in progress to determine the cause of the landing gear failure.

“While there was an anomaly with the left landing gear deployment, the high-quality flight and telemetry data throughout all phases of the approach-and-landing test will allow SNC teams to continue to refine their spacecraft design. SNC and NASA Dryden are currently reviewing the data. As with any space flight test program, there will be anomalies that we can learn from, allowing us to improve our vehicle and accelerate our rate of progress.”

The engineering test article (ETA) is a full sized vehicle.

Dream Chaser is a reusable mini shuttle that launches from the Florida Space Coast atop a United Launch Alliance Atlas V rocket and lands on the shuttle landing facility (SLF) runway at the Kennedy Space Center, like the space shuttle.

“It’s not outfitted for orbital flight. It is outfitted for atmospheric flight tests,” said Marc Sirangelo, Sierra Nevada Corp. vice president and SNC Space Systems chairman told Universe Today previously.

“The best analogy is it’s very similar to what NASA did in the shuttle program with the Enterprise, creating a vehicle that would allow it to do significant flights whose design then would filter into the final vehicle for orbital flight,” Sirangelo told me.

We’ll provide further details as they become known.

Ken Kremer