The Curious History of the Lyrid Meteor Shower

The 2013 Lyrid meteors as seen from Windy Point Vista on Mt. Lemmon, Tucson Arizona. (Credit & copyright Sean Parker Photography. In the Universe Today flickr gallery).

Today we residents of planet Earth meet up with a meteor stream with a strange and bizarre past.

The Lyrid meteors occur annually right around April 21st to the 23rd. A moderate meteor shower, observers in the northern hemisphere can expect to see about 20 meteors in the early morning hours under optimal conditions. Such has been the case for recent years past, and this year’s presence of a waxing gibbous Moon has lowered prospects for this April shower considerably in 2013.

But this has not always been the case with this meteor stream. In fact, we have records of the Lyrids stretching back over the past 2,600 years, farther back than any other meteor shower documented.

The earliest account of this shower comes from a record made by Chinese astronomers in 687 BC, stating that “at midnight, stars dropped down like rain.” Keep in mind that this now famous assertion that is generally attributed to the Lyrids was made by mathematician Johann Gottfried Galle in 1867. It was Galle along with Edmond Weiss who noticed the link between the Lyrids and Comet C/1861 G1 Thatcher discovered six years earlier.

Comet Thatcher was discovered on April 5th, 15 days before it reached perihelion about a third of an astronomical unit (A.U.) from the Earth. Comet Thatcher a periodic comet on a 415 year long orbital period.

But in the early to mid-19th century, the very idea that meteor showers were linked to comets or even non-atmospheric phenomena was still hotly contested.

One singular event more than any other triggered this realization. The Leonid meteor storm of 1833 in the early morning hours of November 13th was a stunning and terrifying spectacle for residents of the U.S eastern seaboard. This shower produces mighty outbursts, often topping a Zenithal Hourly Rate (ZHR) of over a 1,000 once every 33 to 34 years. I witnessed a fine outburst of the Leonids from Kuwait in 1998, and we may be in for a repeat performance from this shower around 2032 or 2033.

There is substantial evidence that the Lyrids may also do the same at an undetermined interval. On April 20th 1803, one of the most famous accounts of a “Lyrid meteor storm” was observed up and down the United States east coast. For example, one letter to the Virginia Gazette states;

“From one until three, those starry meteors seemed to fall from every point in the sky heavens, in such numbers as to resemble a shower of sky rockets.”

Another account published in the Raleigh, North Carolina Register states that:

“The whole hemisphere as far as the extension of the horizon seemed illuminated; the meteors kept no particular direction but appeared to move in every way.”

study of the 1803 Lyrid outburst by W.J. Fisher cites over a dozen accounts of the event and is a fascinating read. Viewers were also primed for the event by the dramatic Leonid storm of 1799 four years earlier.

Interestingly, the Moon was only one day from New phase on the night of the 1803 Lyrids. Prime meteor watching conditions.

An unrelated meteorite fall would also occur four years later over Weston, Connecticut on December 14th, 1807 as recounted by Kathryn Prince in A Professor, A President, and a Meteor. These events would place Yankee politics at odds with the origin of meteors and rocks from the sky.

An apocryphal quote is often attributed to President Thomas Jefferson that highlights the controversy of the day, saying that “I would more easily believe that two Yankee professors would lie than that stones would fall from heaven.”

While both are of cosmogenous origin, no meteorite fall has ever been linked to a meteor shower, which is spawned by dust debris from comets. For example, many in the media erroneously speculated that the Sutter’s Mill meteorite that fell to Earth on the morning of April 22nd, 2012 was in fact a Lyrid meteor.

But a Lyrid may be implicated in another unusual 19th century observation. On April 24th 1874, a professor Scharfarik of Prague, Czechoslovakia was observing the daytime First Quarter Moon with his 4” refractor. The good professor was surprised by an “Apparition on the disc of the Moon of a dazzling white star,” which was “quite sharp and without a perceptible diameter.” Possible suspects are a telescopic meteor moving towards or along the observers’ line of sight or perhaps a Lyrid impacting the dark limb of the Moon.

Moving into the 20th century, rates for the Lyrids have stayed in the ZHR=20 range, with notable peaks of 100+ per hour noted by Japanese observers in 1922 and 100 per hour noted by U.S. observers in 1982.

It should also be noted that another less understood shower radiates from the constellation Lyra in mid-June. First noted Stan Dvorak while hiking in the San Bernardino Mountains in 1966, the June Lyrids produce about 8-10 meteors per hour from June 10 to the 21st. The source of this newly discovered shower is thought to be Comet C/1915 C1 Mellish.

A June Lyrid may have even made its way into modern fiction. As recounted in a July 2004 issue of Sky & Telescope, researchers Marilynn & Donald Olson note the following line from James Joyce’s Ulysses:

“A star, precipitated with great apparent velocity across the firmament from Vega in the Lyre above the zenith.”

Joyce seems to be describing a June Lyrid decades before the shower was officially recognized. The constellation Lyra rides high in the early morning sky for mid-northern latitudes in the early summer months.

All interesting concepts to ponder as we keep an early morning vigil for the Lyrids this week. Could there be more Lyrid storms in the far off future, as Comet Thatcher reaches perihelion once again in the late 23rd century? Could more historical clues of the untold history of this and other showers be awaiting discovery?

Somewhat closer to us in time and space, Paul Wiegert of the University of Ontario has also recently speculated that Comet 2012 S1 ISON may provoke a meteor shower on January 12th, 2014. Regardless of whether ISON turns out to be the “Comet of the Century,” this could be one to watch out for!

  

50 Amazing Facts About Earth

Do you know how much material falls onto Earth from space every day? How many different species there are in the ocean? How far the continents move every year? In honor of Earth Day here’s a very cool infographic that answers those questions about our planet — and 47 more!

Check out the full version below:

50-facts-about-earth3 (1)

And for more interesting information about our planet, click here and here.

Infographic provided by Giraffe Childcare and Early Learning (Dublin, Ireland)

Antares Rocket Launches Successfully

Orbital Sciences Antares rocket successfully launched on its maiden voyage at 5 pm EDT (21:00 UTC) on Sunday, April 21 from the Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility in Virginia. The test flight is serving as the precursor for a demonstration flight of its Cygnus resupply ship to the International Space Station later this year. About 10 minutes after launch, it placed a mass simulator payload to orbit designed to mimic the Cygnus spacecraft’s weight and characteristics. It is in orbit at 250 km (155 miles) in altitude and moving at27,350 km/hr (17,000 mph).

Book Review: The Life and Death of Stars

“The Life and Death of Stars” is a thorough and richly detailed book that will tell you all you want to know about stars. The author, Kenneth R. Lang, is Professor of Astronomy at Tufts University, and he clearly has the knowledge and explanatory ability of someone who has spent his life studying stars. Though its density may deter the casual reader, I found this book engrossing from beginning to end.

If you’ve just been recently bitten by the astronomy bug, this book may not be for you. A more introductory book might be a better choice. But if you’re craving a deeper and more comprehensive understanding of stars, this book will deliver. Make no mistake though; for most readers, it will require some commitment to read your way through this book.

I was never an astrophysics student, but this book seems to me to have a textbook like thoroughness, though not in a dry way. The chapters and topics flow along logically and clearly, with the help of numerous charts and illustrations. For instance, the book starts off with a thorough explanation of light. Since almost all that we know about stars we’ve learned by observing light, where else should a book on astrophysics begin?

From there, the book moves on to chapters titled “Transmutation of the Elements,” “New Stars Arise from the Darkness,” and “Stellar End States,” with other stops in between. The final chapter is titled “Birth, Life, and Death of the Universe.” At the very end of the book, Lang discusses the possible endings of the Universe, and how the mystery of Dark Matter and Dark Energy may dictate the end.

My own understanding of the behaviour and lifecycle of stars has grown enormously from reading this book, and yours will too. For example, if you know that stars form when interstellar gas clouds collapse from their own gravity, but don’t understand exactly how, then “The Life and Death of Stars” will tell you all the detail you’ll need to know. If you know that heavier elements are formed via nucleosynthesis, in the hearts of stars, but you don’t grasp the finer details of that process, then the explanation in this book will bring it to life for you.

Lang is not a populariser of astronomy. His strength is in detailed descriptions, delivered in a comprehensible way. However, he’s not opposed to the occasional poetic turn of phrase: “All stars are impermanent beacons that eventually will cease to shine, vanishing like a circle of fire turning to ash.” True that. He also quotes the Bhagavad Gita, and the poet Shelley.

One of the ways I gauge a book is by my own level of excitement and interest as I’m reading it. I also judge a book by its clarity of explanation and its flow. In both these respects, Lang delivers with this book. After reading it, I’ll definitely be checking out his other books.

“The Life and Death of Stars” broadened and deepened my understanding of all things stellar. It’s a fantastic book, and I wholeheartedly recommend it to Universe Today readers who wish to expand their knowledge of astrophysics.

Earth is the Most Exotic Place In The Universe

While no elements have been found in space that aren't also present on Earth, there are chemical compounds that are unique to other planets, meteorites and found in the space between the stars. Credit: NASA

I’m often asked by students in my community education astronomy classes whether any new elements have been found in outer space unknown on Earth. The answer to the question is no – nature uses the same 98 natural elements to fashion everything from the familiar stars and planets to those in the farthest galaxies we can see. Outside of an occasional compound or mineral, Earth is the place where you’ll find more exotic elements than anywhere else in the universe.

An element is a pure substance made of just one type of atom. What sets one element apart from another is the number of protons in the nuclei of its atoms. Any atom with six protons will always be carbon, 79 protons gold, 94 protons plutonium and 1 proton hydrogen. The proton number is also the element’s atomic number on the periodic table of elements. Elements in the table are arranged according to their atomic number.

Atoms are made of protons, neutrons and orbiting electrons. The number of protons in atom's nucleus makes it unique from all the others. Hydrogen, the simplest element, has one while carbon has six.
Atoms are made of protons, neutrons and orbiting electrons. The number of protons in atom’s nucleus makes it unique from all the others. Hydrogen, the simplest element, has one; carbon has six.

The two most common elements are hydrogen and helium, numbers 1 and 2 in the periodic table; together they make up 98% of all the visible matter in the universe. The remaining 2% includes everything else from lightweight lithium (number 3) all the way up to californium (98), the heaviest natural element found on Earth and in the stars. Californium is unstable and “decays” into simpler elements. Although scientists make it in the lab by bombarding berkelium (97) with neutrons, trace amounts of this very rare element are found naturally in rich uranium deposits.

When I was in high school studying chemistry, the periodic table of elements ended at Lawrencium (103). At present there are 118 elements, the most recent one created in the lab being ununoctium (you-nah-NOC-tee-um). Matter of fact, all the elements beyond 98 are artificial, brought to life in nuclear reactors or in particle accelerator experiments. They live very short lives. With so many positively-charged protons pushing against one another in their nuclei, these elements quickly break apart into simpler ones in a process called radioactive decay.

Artist's concept of the first stars in the Universe turning on some 200 million years after the Big Bang. These first suns were made of almost pure hydrogen and helium. They and later generations of stars cooked up the heavier elements from these simple ones. Credit: NASA/WMAP Science Team
Artist’s concept of the first stars in the Universe turning on some 200 million years after the Big Bang. These first suns were made of almost pure hydrogen and helium. They and later generations cooked up heavier elements that were later incorporated into the sun and us. Credit: NASA/WMAP Science Team

Back at the time of the Big Bang, when the universe sprang into existence, only the simplest elements – hydrogen, helium and trace amounts of lithium – were cooked up. You can’t build a planet from such fluffy stuff. It took the first generation of stars, which formed from these basic building blocks, to synthesize more complicated elements like carbon, oxygen, sulfur and the like via nuclear fusion in their cores.

When the stars exploded as supernovae, not only were these brand new elements blasted into space, but the enormous heat and pressure during the blast built even heavier elements like gold, copper, mercury and lead. All became incorporated in a second generation of stars. And a third.

The 2% of star-made elements, which include carbon, oxygen, nitrogen and silicon among others, went to build the planets and later became essential for life. We’re made of highly processed material you and I. The atoms of our beings have been in and out of the cores of several generations of stars. Think about this good and hard and you might just get in touch with your own “inner star”.

Common table salt is formed of tight-fitting atoms of sodium and chlorine. Each elements has its own individual character - one's a flammable metal (sodium), the other a dangerous gas. Put them together and you create a safe, tasty edible. Credit: Wikipedia
Common table salt is formed of tight-fitting atoms of sodium and chlorine. Each elements has its own individual character – one’s a flammable metal (sodium), the other a dangerous gas. Put them together and out comes a safe, tasty seasoning. Credit: Wikipedia

Let’s reframe the question about exotic materials in space not present on Earth. Instead of elements, if we look at compounds, we hit paydirt. A compound is also a pure substance but consists of two or more chemical elements joined together. Familiar compounds include water (two hydrogens joined to one oxygen) and salt (one sodium and one chlorine).

A selection of molecules (chemical compounds) including water found in the Orion Nebula detected by the Herschel Space Telescope. Credit: ESA, HEXOS and the HIFI Consortium E. Bergin
A selection of molecules (chemical compounds) including water found in the Orion Nebula detected by the Herschel Space Telescope. Credit: ESA, HEXOS and the HIFI Consortium E. Bergin

Astronomers have found about 220 compounds or molecules in outer space many of them with siblings on Earth but some alien. We don’t have to look far to find them since a few have been delivered right to our doorstep as rocky packages called meteorites.  Here’s a short list of new minerals that formed within asteroids (where meteorites originate) under conditions very different from those found on Earth:

Barringerite – a metallic compound made of iron, nickel and phosphorus
Oldhamite – brown mineral made of calcium, magnesium and sulfur
Kosmochlor  – green mineral containing calcium, chromium, silicon and oxygen

How about new stuff on planets and comets? Astronomers have discovered compounds in the atmospheres of the giant planets Jupiter, Saturn, Uranus and Neptune like silane (silicon-hydrogen), arsine (arsenic-hydrogen) and phosphine (phosphorus-hydrogen) that don’t exist naturally on Earth. Humans have created all three in the lab and put them to good use in various industries including the manufacture of semi-conductors.

Helium was first discovered in the spectrum of the sun by French astronomer Pierre Janssen in 1868 by observing sunlight through a prism during an eclipse. It was discovered on Earth in 1895. Credit: Bob King
Helium, the gas that floats our balloons, was first discovered in the spectrum of the sun by French astronomer Pierre Janssen in during a solar eclipse in 1868. Scientists finally found it on Earth in 1895. Click to learn the helium story. Credit: Bob King

And then there’s Brownleeite, a manganese silicide found in 2003 in a dust particle shed by comet 26P/Grigg-Skjellerup. Moving beyond the solar system, astronomers see unusual long-chained carbon molecules in space that couldn’t form on Earth because oxygen would tear them apart. Space is their safe haven.

So, Earth is the location in the Universe where you’ll find more exotic elements than anywhere else. Thanks to human activity and the complicated molecules that wound together to form life, Earth’s the most exotic place in the universe.

Astrophoto: Paint the Sky with Clouds

Composite of 300 images of the sky at sunset over Palmerston North, New Zealand. Credit and copyright: Manoj Kesavan.

Here’s a great – and beautiful! – example of what you can do with image stacking. Manoj Kesavan, an avid astrophotographer based at Massey University, New Zealand shot 300 images during 45 minutes at sunset (6:45 pm to 7.30 pm local time) from Palmerston North, New Zealand. “It’s a stack of 300 images, which means virtually putting all 300 photos on top of each other,” Kesavan explained via email. “So the cloud formation, movement and the transformation of sky color from blue to purple to red are captured on one single final image. And the saturation has been pumped up during the post processing.”

Kesavan said he shot this as part of an upcoming timelapse, using a Canon 7D using SIgma 10-20mm at 10mm, iso 100 & f8.

It’s a beautiful result and we look forward to seeing the timelapse! See more of Kesavan’s photography at his Facebook page or Flickr stream.

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.

A New Look at the Horsehead Nebula for Hubble’s 23rd Anniversary

A new view of the Horsehead Nebula in infrared. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).

Here’s the iconic Horsehead Nebula as we’ve not seen it before. As the Hubble team so poetically puts it, the nebula looks “like an apparition rising from whitecaps of interstellar foam.” The new image of the Horsehead was photographed in celebration of the 23rd anniversary of the launch of Hubble aboard the space shuttle Discovery, on April 24, 1990.

Can you believe the Hubble Space Telescope has been in space for 23 years? … and it’s been churning out great images for almost 20 years since it was fixed in space during the first Hubble servicing mission in 1993.

This view shows the nebula in infrared wavelengths. When seen in optical light (see below), it appears dark and shadowy, but is “transparent and ethereal when seen in the infrared, represented here with visible shades. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that are easily seen in infrared light,” the Hubble team said.

Gas clouds surrounding the Horsehead have already dissipated, but the tip of the jutting pillar contains a slightly higher density of hydrogen and helium, laced with dust. This casts a shadow that protects material behind it from being photo-evaporated, and a pillar structure forms. Astronomers estimate that the Horsehead formation has about five million years left before it too disintegrates.

The Horsehead Nebula is part of a much larger complex in the constellation Orion. Known collectively as the Orion Molecular Cloud, it also houses other famous objects such as the Great Orion Nebula (M42), the Flame Nebula, and Barnard’s Loop. At about 1,500 light-years away, this complex is one of the nearest and most easily photographed regions in which massive stars are being formed.

Hubble’s pairing of infrared sensitivity and unparalleled resolution offers a tantalizing hint of what the upcoming James Webb Space Telescope, set for launch in 2018, will be able to do.

Here’s a view in optical from Hubble:

The Horsehead Nebula is a cold, dark cloud of gas and dust, silhouetted against the bright nebula IC 434. The bright area at the top left edge is a young star still embedded in its nursery of gas and dust. Image Credit: NASA, NOAO, ESA and The Hubble Heritage Team (STScI/AURA)
The Horsehead Nebula is a cold, dark cloud of gas and dust, silhouetted against the bright nebula IC 434. The bright area at the top left edge is a young star still embedded in its nursery of gas and dust.
Image Credit: NASA, NOAO, ESA and The Hubble Heritage Team (STScI/AURA)

For more details, see the HubbleSite

How Micrometeoroid Impacts Pose a Danger for Today’s Spacewalk

Astronauts perform an EVA outside of the ISS during STS-110. (Credt: NASA).



Video streaming by Ustream

Our very own International Space Station is in the cosmic crosshairs.

As cosmonauts are to begin Extra Vehicular Activity (EVA) this morning to perform routine maintenance, an article reminding us of the hazards of such activity came to us via NASA’s Orbital Debris Quarterly Newsletter.

The problem is Micrometeoroid and Orbital Debris (MMOD) impacts. These are nothing new. Pits and tiny cratering has been observed during post-flight inspections of space shuttle orbiters. But this is the first time we’d seen talk of damage caused by tiny impacts on the exterior of the International Space Station.

The handrails are a particularly sensitive area of concern.

The study examined damage incurred on handrails exposed to the environment of space for years on end. These present a hazard to spacewalking astronauts who rely on the handles to move about. These craters often become spalled, presenting a sharp metal rim raised from the surface of the handle.

Close-up of a micro-meteoroid impact on a handrail. (Credit: NASA/JSC Image & Science Analysis Group).
Close-up of a micro-meteoroid impact on a handrail. (Credit: NASA/JSC Image & Science Analysis Group).

Of course, these razor sharp rims present a problem, especially to space suit gloves. One 34.8 centimeter long handrail returned on the final Space Shuttle mission STS-135 had six impact craters along its length. The handrail had been in service and exposed to the vacuum of space for 8.7 years.

Craters as large as 1.85 millimetres (mm) in diameter with raised lips of 0.33mm have been observed on post-inspection. In studies conducted by NASA engineers, craters with lip heights as little as 0.25mm have been sufficient to snag and tear spacesuit gloves.

There have also been reported incidents of glove tears during EVAs conducted from the ISS over the years. For example, the report cites a tear noticed by astronaut Rick Mastracchio during STS-118 that cut the EVA short.

Analysis of an impact seen on STS-122. (Credit: NASA
Analysis of an impact seen on STS-122. (Credit: NASA/JSC Image & Science Analysis Group).

To protect astronauts and cosmonauts during EVAs, the following measures have been instituted:

–          Toughening space suit gloves by adding reinforcement to areas exposed to potential MMOD damage.

–          Monitoring and analyzing MMOD impacts along handrails and maintaining a database of problem areas.

–          Equipping spacewalkers with the ability to cover and/or repair hazardous MMOD areas during spacewalks.

The studies were carried out by the Johnson Space Center Hypervelocity Impact Technology Group in conjunction with a test facility at White Sands, New Mexico. Astronaut Rick Mastracchio can also be seen talking about the hazards of spacewalking on this video.

Today’s 6 hour EVA by cosmonauts Vinogradov & Romanenko begins at 14:06 UT 10:06AM EDT.

This will be the 32nd Russian EVA from the International Space Station and will use the Pirs hatch on Zvezda.

Tasks include retrieving and installing experiment packages and replacing a defective retro-reflector device on the station’s exterior.  The device is a navigational aid necessary for the Albert Einstein ATV-4 mission headed to the ISS on June 5th.

Progress 51P is also scheduled to launch towards the ISS next week on April 24 for docking on April 26th.

Debris in Low Earth Orbit is becoming an increasing concern. The Chinese anti-satellite test in 2007 and the collision of Kosmos 2251 and Iridium 33 in 2009 have increased hazards to the ISS. Many fear that a tipping point, known as an ablation cascade, could eventually occur with one collision showering LEO with debris that in turn trigger many more. The ISS was only finished in 2011, and it would be a tragic loss to see it abandoned due to a catastrophic collision only years after completion.

More than once, ISS crew members have sat out a debris conjunction that was too close to call in their Soyuz life boats, ready to evacuate the station if necessary. DAMs (Debris Avoidance Maneuvers) are now common for the ISS throughout the year.

Several ideas have been proposed to deal with space debris. In the past year, NanoSail-2D demonstrated the ability to deploy a solar sail from a satellite for reentry at the end of a spacecraft’s life span. Such technology may be standard equipment on future satellites.

Expect reentries to increase as we near the solar maximum for cycle #24 in late 2013 & early 2014. This occurs because the exosphere of Earth “puffs out” due to increased solar activity and increases drag on satellites in low Earth orbit.

All food for thought as we watch today’s EVA… space travel is never routine!

The April 2013 edition of the Orbital Debris Quarterly News is available for free online.