Mercury Archives

November 13, 2016November 14, 2016 by Ken Kremer

America’s Pioneering Astronauts Honored with new ‘Heroes and Legends’ Attraction at Kennedy Space Center

Grand opening ceremony for the ‘Heroes and Legends’ attraction on Nov. 11, 2016 at the Kennedy Space Center Visitor Complex in Florida and attended by more than 25 veteran and current NASA astronauts. It includes the new home of the U.S. Astronaut Hall of Fame, presented by Boeing. In addition to displays honoring the 93 Americans currently enshrined in the hall, the facility looks back to the pioneering efforts of Mercury, Gemini and Apollo. It provides the background and context for space exploration and the legendary men and women who pioneered the nation's journey into space. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER VISITOR COMPLEX, FL – America’s pioneering astronauts who braved the perils of the unknown and put their lives on the line at the dawn of the space age atop mighty rockets that propelled our hopes and dreams into the new frontier of outer space and culminated with NASA’s Apollo lunar landings, are being honored with the eye popping new ‘Heroes and Legends’ attraction at the Kennedy Space Center Visitor Complex (KSCVC) in Florida.

With fanfare and a fireworks display perfectly timed for Veterans Day, ‘Heroes and Legends’ opened its doors to the public on Friday, November 11, 2016, during a gala ceremony attended by more than 25 veteran and current NASA astronauts, including revered Gemini and Apollo space program astronauts Buzz Aldrin, Jim Lovell, Charlie Duke, Tom Stafford, Dave Scott, Walt Cunningham and Al Worden – and throngs of thrilled members of the general public who traveled here as eyewitnesses from all across the globe.

Aldrin, Scott, and Duke walked on the Moon during the Apollo 11, 15 and 16 missions.

Also on hand were the adult children of the late-astronauts Alan Shepard (first American in space) and Neil Armstrong (first man to walk on the Moon), as well as representatives from NASA, The Boeing Company (sponsor) and park operator Delaware North – for the engaging program hosted by Master of Ceremonies John Zarrella, CNN’s well known and now retired space correspondent.

The stunning new ‘Heroes and Legends’ attraction is perfectly positioned just inside the entrance to the KSC Visitor Complex to greet visitors upon their arrival with an awe inspiring sense of what it was like to embark on the very first human journey’s into space by the pioneers who made it all possible ! And when every step along the way unveiled heretofore unknown treasures into the origin of us and our place in the Universe.

Upon entering the park visitors will immediately and surely be mesmerized by a gigantic bas relief sculpture recreating an iconic photo of America’s first astronauts – the Mercury 7 astronauts; Scott Carpenter, Gordon Cooper, John Glenn, Gus Grissom, Wally Schirra, Alan Shepard, and Deke Slayton.

“With all the drama of an actual trip to space, guests of Kennedy Space Center Visitor Complex in Florida will be greeted with a dramatic sense of arrival with the new Heroes & Legends featuring the U.S. Astronaut Hall of Fame® presented by Boeing. Positioned just inside the entrance, the attraction sets the stage for a richer park experience by providing the emotional background and context for space exploration and the legendary men and women who pioneered our journey into space,” according to a description from Delaware North Companies Parks and Resorts, which operates the KSC visitor complex.

“Designed to be the first stop upon entering Kennedy Space Center Visitor Complex, Heroes & Legends uses the early years of the space program to explore the concept of heroism, and the qualities that define the individuals who inspired their generation.”

Astronauts cut the ribbon during Grand opening ceremony for the ‘Heroes and Legends’ attraction on Nov. 11, 2016 at the Kennedy Space Center Visitor Complex in Florida, led by Kennedy Space Center Director Bob Cabana, a former space shuttle astronaut and member of the Astronaut Hall of Fame, during the ceremony. Credit: Julian Leek

“I hope that all of you, when you get to see Heroes and Legends, you’re inspired,” said Kennedy Space Center Director Bob Cabana, a former space shuttle astronaut and member of the Astronaut Hall of Fame, during the ceremony.

“The children today can see that there is so much more they can reach for if they apply themselves and do well.”

“I think people a thousand years from now are going to be happy to see these artifacts and relics,” Apollo 15 command module pilot Al Worden told the crowd.

“We have so much on display here with a Saturn V, Space Shuttle Atlantis. People will think back and see the wonderful days we had here. And I guess in that same vein, that makes me a relic too.”

Furthermore, ‘Heroes and Legends’ is now very conveniently housed inside the new home of the U.S. Astronaut Hall of Fame (AHOF) – making for a unified space exploration experience for park visitors. AHOF previously was located at another off site park facility some seven miles outside and west of the Visitor Complex.

The bas relief measures 30 feet tall and 40 feet wide. It is made put of fiberglass and was digitally sculpted, carved by CNC machines and juts out from the side of the new into the new 37,000 square foot U.S. Astronaut Hall of Fame (AHOF) structure.

To date 93 astronauts have been inducted into the Astronaut Hall of Fame spanning the Mercury, Gemini, Apollo and Space Shuttle programs.

“I don’t consider myself a hero like say, Charles Lindbergh,” said Jim Lovell, a member of the Astronaut Hall of Fame and Apollo 13 commander, when asked by Zarrella what it feels like to be considered an American space hero. “I just did what was proper and exciting — something for my country and my family. I guess I’m just a lucky guy.”

The astronauts are also quick to say that they were supported by hundreds of thousands of dedicated people working in the space program to make Apollo happen.

“It important to remember all the dedication and hard work that it took from those of us involved in the astronaut program, but also the support we received from Kennedy and all the contractors involved in Apollo,” said Apollo 16 moonwalker Charlie Duke.

“400,000 people made it possible for 24 of us to go to the Moon.”
“So dream big, aim high!” exclaimed Duke.

“Hopefully this is an inspiration to you and your kids and grandkids.”

Construction of the facility by Falcon’s Treehouse, an Orlando-based design firm began in the fall of 2015.

“We’re focusing on a story to create what we consider a ‘launch pad’ for our visitors,” said Therrin Protze, the Delaware North chief operating officer of the Visitor Complex. “This is an opportunity to learn about the amazing attributes of our heroes behind the historical events that have shaped the way we look at space, the world and the future.

“We are grateful to NASA for allowing us to tell the NASA story to millions of guests from all over the world,” Protze said.

Visitors walk up a sweeping ramp to enter the Heroes and Legends experience.

After visitors walk through the doors, they will be immersed by two successive video presentations and finally the Hall of Fame exhibit hall.

Here’s a detailed description:

• In the stunning 360-degree discovery bay, What is a Hero?, guests will explore how society defines heroism through diverse perspectives. Each examination of heroism starts with the following questions: What is a hero; Who are the heroes of our time; and What does it take to be a hero? During the seven-minute presentation, the historic beginning of the space race is acknowledged as the impetus for America’s push to the stars in NASA’s early years and the rivalry between the United States and the Soviet Union during the Cold War.

• Through the Eyes of a Hero is a custom-built theater featuring a multi-sensory experience during which guests will vicariously join NASA’s heroes and legends on the most perilous stages of their adventures. Artistically choreographed lighting and 3D imagery will be enhanced by intense, deeply resonant sound effects to create the sensation of being “in the moment.” The seven and one-half minute show takes guests on an intimate journey with four space-age heroes to fully immerse them in the awe, excitement and dangers of the first crewed space program missions.

• The third experience, A Hero Is…, offers interactive exhibits that highlight the nine different attributes of our history making astronauts: inspired, curious, passionate, tenacious, disciplined, confident, courageous, principled and selfless. A collection of nine exhibit modules will explore each aforementioned attribute, through the actual experiences of NASA’s astronauts. Their stories are enhanced with memorabilia from the astronaut or the space program.

A statue of astronaut Alan Shepard, America's first person in space, stands just inside the doors to the U.S. Astronaut Hall of Fame. The exhibit is housed in a rotunda and connects the visitor to each of the astronaut inductees through state-of-the-art interactive technology. Credit: Lane Hermann — A statue of astronaut Alan Shepard, America’s first person in space, stands just inside the doors to the U.S. Astronaut Hall of Fame. The exhibit is housed in a rotunda and connects the visitor to each of the astronaut inductees through state-of-the-art interactive technology. Credit: Lane Hermann

Priceless historic artifacts on display also include two flown capsules from Mercury and Gemini; the Sigma 7 Mercury spacecraft piloted by Wally Schirra during his six-orbit mission in October 1962 and the Gemini IX capsule flown by Tom Stafford and Gene Cernan for three days in June 1966.

The Sigma 7 Mercury spacecraft piloted by astronaut Wally Schirra during his nine-hour, 13-minute mission of six orbits on October 3, 1962 mated to a human rated Mercury Redstone rocket (MR-6) is on display in the Heroes and Legends display at the Kennedy Space Center Visitor Complex in Florida. Credit: Ken Kremer/kenkremer.com

The human rated Mercury Redstone-6 (MR-6) is also on display and dramatically mated to the Schirra’s Sigma 7 Mercury capsule.

Another room houses the original consoles of the Mercury Mission Control room with the world map that was used to follow the path of John Glenn’s Mercury capsule Friendship 7 between tracking stations when he became the first American to orbit Earth in 1962.

Interactive features in the KSCVC Heroes and Legends attraction include the original consoles of the Mercury Mission Control room with the world map that was used to follow the path of the John Glenn capsule Friendship 7 between tracking stations. Credit: Ken Kremer/kenkremer.com — Interactive features in the KSCVC Heroes and Legends attraction include the original consoles of the Mercury Mission Control room with the world map that was used to follow the path of the John Glenn capsule Friendship 7 between tracking stations in 1962. Credit: Ken Kremer/kenkremer.com

Further details about ‘Heroes and Legends, the U.S. Astronaut Hall of Fame and all other attractions are available at the Kennedy Space Center Visitor Complex website: https://www.kennedyspacecenter.com/

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

Ken Kremer

………….

Learn more about Heroes and Legends at KSCVC, GOES-R weather satellite, OSIRIS-REx, InSight Mars lander, SpaceX missions, Juno at Jupiter, SpaceX CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:

Nov 17-20: “GOES-R weather satellite launch, OSIRIS-REx launch, SpaceX missions/launches to ISS on CRS-9, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

July 26, 2016 by David Dickinson

Celestial Photobomb: Rare Occultation of Mercury by the Moon Set for Next Week

Mercury and the Moon over the ramparts of Assilah, Morocco. Photo by author

Have you caught sight of Mercury yet? This coming week is a good time to try, looking low to the west at dusk. We just managed to to nab it with binoculars for the first time during the current apparition this past Sunday from the rooftop of our Air BnB in Casablanca, Morocco.

Mercury is a tough grab under any circumstance, that’s for sure. Brilliant Venus and Jupiter make great guides to finding the elusive planet in late July, as it ping-pongs between the two. The waxing crescent Moon joins the scene in the first week of August, and for a very lucky few, actually occults (passes in front of ) the diminutive innermost world shortly after passing New.

Mercury (arrowed) near the Moon on the morning of June 3rd, 2016. Image credit: Dave Dickinson.

Here’s the low down on everything Mercurial, and circumstances for the coming weeks.

Mercury passes 18′ from the star Regulus on Saturday, July 30^th at 19:00 Universal Time (UT), representing the closest passage of a planet near a first magnitude star for 2016.

The Moon then reaches New phase, marking the start of lunation 1158 on August 2^nd at 20:45 UT. The Moon then moves on to occult Mercury on Thursday, August 4^th at 22:00 UT, just over 48 hours later. The occultation is visible at dusk for observers based in southern Chile and southern Argentina. The rest of us see a close pass. Note that although it is a miss for North America, viewers based on the continent share the same colongitude and will see Mercury only a degree off of the northern limb of the Moon on the night of August 4^th. Mercury shines at magnitude +0.01, and presents a 67% illuminated disk 6.3” in size, while the Moon is a slender 5% illuminated.

Occultations of Mercury for 2016. Credit: Occult 4.2. (click image to enlarge).

How early can you see the waxing crescent Moon? Catching the Moon with the naked eye under transparent clear skies isn’t usually difficult when it passes 20 hours old. This cycle, first sightings favor South Africa westward on the night of August 3^rd.

Mercury reaches greatest elongation 27.4 degrees east of the Sun 12 days after this occultation on August 16^th.

How rare is it? Well occultations of Mercury by the Moon are the toughest to catch of all the naked eye planets, owing to the fact that the planet never strays far from the Sun. Nearly all of these events go unwitnessed, as they occur mainly under daytime skies. And while you can observe Mercury in the daytime near greatest elongation with a telescope, safety precautions need to be taken to assure the Sun is physically blocked from view. Astronomers of yore did exactly that, hoping to glimpse fleeting detail on Mercury while it was perched higher in the sky above the murk of the atmosphere low to the horizon.

In fact, a quick search of ye ole web reveals very few convincing captures of an occultation of Mercury (see the video above). The closest grab thus far comes from astrophotographer Cory Schmitz on June 3^rd 2016 based in South Africa:

Image credit: — Can you see it? The Moon about to occult Mercury on June 3rd. Image credit and copyright: Cory Schmitz.

Can’t wait til next week? The Moon crosses the Hyades open star cluster this week, occulting several stars along the way. The action occurs on the morning of Friday, July 29^th culminating with an occultation of +1 magnitude Aldebaran by the 23% illuminated Moon. Texas and Mexico are well-placed to see this event under dark skies. A small confession: we actually prefer occultations of planets and stars by the waxing Moon, as the dark edge of the Moon is leading during ingress, making it much easier to witness and the exact moment the Moon blots out the object.

Still want more? The Moon actually goes on to occult Jupiter on August 6^th for the South Pacific. Viewers farther west in southeast Asia might just spy this one in the daytime. This is the second occultation of Jupiter by the Moon in a series of four in 2016.

Looking west on the evening of August 4th. Image credit: Stellarium.

Keep and eye on those planets in August, as they’re now all currently visible in the dusk sky. The Moon, Regulus and Venus also form a tight five degree triangle on the evening of August 4^th, followed by a slightly wider grouping of Venus, Jupiter and the Moon around August 25^th.

More to come on that soon. Be sure to check the planet Mercury off of your life list this coming week, using the nearby waxing crescent Moon as a guide.

May 9, 2016May 19, 2019 by David Dickinson

Images of Today’s Transit of Mercury From Around the World

Mercury Transit — Mercury meets the Sun in Hydrogen Alpha. Image credit and copyright: Brendan Martin @HASungazer

Lead image credit: Brendan Martin.

(Note: Awesome images are being added as they come in!)

Update: Here’s two more amazing videos of yesterday’s transit of Mercury that have come our way. First: double solar transits featuring Mercury, the International Space Station and a low flying plane right here in the skies of good old planet Earth courtesy of (who else?) Thierry Legault:

And here’s one of the very few sequences we’ve seen of the transit with foreground, captured at sunset by Gadi Eidelheit based in Israel:

And finally, check out this amazing (and mesmerizing) animation of Mercury racing across the Sun, courtesy of the Big Bear Solar Observatory!

It’s not every day you get to see a planet pass in front of the Sun.

But today, skywatchers worldwide got to see just that, as diminutive Mercury passed in front of the disk of the Sun as seen from the Earth. This was the first transit of Mercury across the face of the Sun since November 8th, 2006, and the last one until November 11th, 2019. Continue reading “Images of Today’s Transit of Mercury From Around the World”

May 8, 2016May 8, 2016 by Bob King

Give Mom the Aurora Tonight / Mercury Transit Update

A coronal aurora twists overhead in this photo taken early on May 8 from near Duluth, Minn. Credit: Bob King

Skywatchers across the northern tier of states, the Midwest and southern Canada were treated to a spectacular display of the aurora borealis last night. More may be on tap for tonight. Credit: Bob King — Skywatchers across the northern tier of states, the Midwest and southern Canada were treated to a spectacular display of the aurora borealis last night. More may be on tap for tonight — in honor of Mother’s Day of course! Credit: Bob King

Simple choices can sometimes lead to dramatic turns of events in our lives. Before turning in for the night last night, I opened the front door for one last look at the night sky. A brighter-than-normal auroral arc arched over the northern horizon. Although no geomagnetic activity had been forecast, there was something about that arc that hinted of possibility.

It was 11:30 at the time, and it would have been easy to go to bed, but I figured one quick drive north for a better look couldn’t hurt. Ten minutes later the sky exploded. The arc subdivided into individual pillars of light that stretched by degrees until they reached the zenith and beyond. Rhythmic ripples of light – much like the regular beat of waves on a beach — pulsed upward through the display. You can’t see a chill going up your spine, but if you could, this is what it would look like.

Auroras can be caused by huge eruptions of subatomic particles from the Sun’s corona called CMEs or coronal mass ejections, but they can also be sparked by holes in the solar magnetic canopy. Coronal holes show up as blank regions in photos of the Sun taken in far ultraviolet and X-ray light. Bright magnetic loops restrain the constant leakage of electrons and protons from the Sun called the solar wind. But holes allow these particles to fly away into space at high speed. Last night’s aurora traces its origin back to one of these holes.

Visualization of the solar wind encountering Earth's magnetic "defenses" known as the magnetosphere. Clouds of southward-pointing plasma are able to peel back layers of the Sun-facing bubble and stack them into layers on the planet's nightside (center, right). The layers can be squeezed tightly enough to reconnect and deliver solar electrons (yellow sparkles) directly into the upper atmosphere to create the aurora. Credit: JPL — Both a bar magnet (left) and Earth are surrounded by magnetic fields with north and south poles. Earth’s field is shaped by charged particles – electrons and protons – flowing from the sun called the solar wind. Credit: Andy Washnik (left) and NASA

The subatomic particles in the gusty wind come bundled with their own magnetic field with a plus or positive pole and a minus or negative pole. Recall that an ordinary bar magnet also has a “+” and “-” pole, and that like poles repel and opposite poles attract. Earth likewise has magnetic poles which anchor a large bubble of magnetism around the planet called the magnetosphere.

Field lines in the magnetosphere — those invisible lines of magnetic force around every magnet — point toward the north pole. When the field lines in the solar wind also point north, there’s little interaction between the two, almost like two magnets repelling one another. But if the cloud’s lines of magnetic force point south, they can link directly into Earth’s magnetic field like two magnets snapping together. Particles, primarily electrons, stream willy-nilly at high speed down Earth’s magnetic field lines like a zillion firefighters zipping down fire poles. They crash directly into molecules and atoms of oxygen and nitrogen around 60-100 miles overhead, which absorb the energy and then release it moments later in bursts of green and red light.

View of the eastern sky during the peak of this morning's aurora. Credit: Bob King — View of the eastern sky during the peak of this morning’s aurora. Credit: Bob King

So do great forces act on the tiniest of things to produce a vibrant display of northern lights. Last night’s show began at nightfall and lasted into dawn. Good news! The latest forecast calls for another round of aurora tonight from about 7 p.m. to 1 a.m. CDT (0-6 hours UT). Only minor G1 storming (K index =5) is expected, but that was last night’s expectation, too. Like the weather, the aurora can be tricky to pin down. Instead of a G1, we got a G3 or strong storm. No one’s complaining.

So if you’re looking for that perfect last minute Mother’s Day gift, take your mom to a place with a good view of the northern sky and start looking at the end of dusk for activity. Displays often begin with a low, “quiet” arc and amp up from there.

The camera recorded pale purple and red but the primary color visible to the eye was green. Credit: Bob Kin — The camera recorded pale purple, red and green, but the primary color visible to the eye was green. Cameras capture far more color than what the naked eye sees because even faint colors increase in intensity during a time exposure. Details: ISO 800, f/2.8, 13 seconds. Credit: Bob King

Aurora or not, tomorrow features a big event many of us have anticipated for years — the transit of Mercury. You’ll find everything you’ll need to know in this earlier story, but to recap, Mercury will cross directly in front of the Sun during the late morning-early evening for European observers and from around sunrise (or before) through late morning-early afternoon for skywatchers in the Americas. Because the planet is tiny and the Sun deadly bright, you’ll need a small telescope capped with a safe solar filter to watch the event. Remember, never look directly at the Sun at any time.

Nov. 15, 1999 transit of Mercury photographed in UV light by the TRACE satellite. Credit: NASA

If you’re greeted with cloudy skies or live where the transit can’t be seen, be sure to check out astronomer Gianluca Masi’s live stream of the event. He’ll hook you up starting at 11:00 UT (6 a.m. CDT) tomorrow.

The table below includes the times across the major time zones in the continental U.S. for Monday May 9:

Time Zone	Eastern (EDT)	Central (CDT)	Mountain (MDT)	Pacific (PDT)
Transit start	7:12 a.m.	6:12 a.m.	5:12 a.m.	Not visible
Mid-transit	10:57 a.m.	9:57 a.m.	8:57 a.m.	7:57 a.m.
Transit end	2:42 p.m.	1:42 p.m.	12:42 p.m.	11:42 a.m.

April 29, 2016April 29, 2016 by Matt Williams

How Do We Terraform Mercury?

Images of Mercury's northern polar region, provided by MESSENGER. Credit: NASA/JPL

Welcome back to another installment in the “Definitive Guide to Terraforming” series! We complete our tour of the Solar System with the planet Mercury. Someday, humans could make a home on this hostile planet, leading to the first Hermians!

The planet Mercury is an intensely hot place. As the nearest planet to our Sun, surface temperatures can get up to a scorching 700 K (427° C). Ah, but there’s a flip-side to that coin. Due to it having no atmosphere to speak of, Mercury only experiences intensely hot conditions on the side that is directly facing the Sun. On the nighttime side, temperatures drop to well below freezing, as low as 100 K (-173° C).

Due to its low orbital period and slow rate of rotation, the nighttime side remains in the dark for an extended period of time. What’s more, in the northern polar region, which is permanently shaded, conditions are cold enough that water is able to exist there in ice form. Because of this, and a few reasons besides, there are many who believe that humanity could colonize and even terraform parts of Mercury someday.

Continue reading “How Do We Terraform Mercury?”

April 15, 2016April 27, 2016 by Bob King

How to Safely Watch Mercury Transit the Sun on May 9

The Solar and Heliospheric Observatory (SOHO) took these photos of Mercury during its last transit of the Sun on Nov. 8, 2006. Credit: NASA/ESA

Be sure to mark your calendar for May 9. On that day, the Solar System’s most elusive planet will pass directly in front of the Sun. The special event, called a transit, happens infrequently. The last Mercury transit occurred more than 10 years ago, so many of us can’t wait for this next. Remember how cool it was to see Venus transit the Sun in 2008 and again in 2012? The views will be similar with one big difference: Mercury’s a lot smaller and farther away than Venus, so you’ll need a telescope. Not a big scope, but something that magnifies at least 30x. Mercury will span just 10 arc seconds, making it only a sixth as big as Venus.

Two basic types of safe solar filters for telescopes: an aluminized polymer such as Baader film and a glass solar filter made for a particular make and model. Credit: Bob King — Two basic types of safe solar filters for telescopes: an aluminized polymer such as Baader film and a dedicated glass solar filter for a particular make and model. Credit: Bob King

That also means you’ll need a solar filter for your telescope. If you’ve put off buying one, now’s the time to plunk down that credit card. Safe, quality filters are available from many sources including Orion Telescopes, Thousand Oaks Optical, Kendrick Astro Instruments and Amazon.com.

Map showing Mercury's path across the Sun with three key times: transit start at left; midpoint and transit end. Credit: Tom Ruen with additions by author — Map showing Mercury’s path across the Sun at three key points on May 9: transit start or ingress (left); midpoint and transit end or egress (right). Credit: Tom Ruen with additions by author

If I might make a suggestion, consider buying a sheet of Baader AstroSolar aluminized polyester film and cutting it to size to make your own filter. Although the film’s crinkly texture might make you think it’s flimsy or of poor optical quality, don’t be deceived by appearances.

The material yields both excellent contrast and a pleasing neutral-colored solar image. You can purchase any of several different-sized films to suit your needs either from Astro-Physics or on Amazon.com. Prices range from $40-90.

Nov. 8, 2006 Transit of Mercury by Dave Kodama

With filter material in hand, just follow these instructions to make your own, snug-fitting telescopic solar filter. Even I can do it, and I kid you not that I’m a total klutz when it comes to building things. If for whatever reason you can’t get a filter, go to Plan B. Put a low power eyepiece in your scope and project an image of the Sun onto a sheet of white paper a foot or two behind the eyepiece.

World map showing where the May 9-10 Mercury transit will be visible. Universal times of the four contact points during the event are given at upper left. Credit: Xavier — World map showing where the May 9-10 Mercury transit will be visible. Universal times of the four key contacts (see below for details), mid-transit time and position angle on the Sun’s limb where the planet will first appear and disappear are given at upper left. Credit: Xavier M. Jubier

Since May 9th is a Monday, I’ve a hunch a few of you will be taking the day off. If you can’t, pack a telescope and set it up during lunch hour to share the view with your colleagues. Mercury will spend a leisurely 7 1/2 hours slowly crawling across the Sun’s face, traveling from east to west. The entire transit will be visible across the eastern half of the U.S., most of South America, eastern and central Canada, western Africa and much of western Europe. For the western U.S., Alaska and Hawaii the Sun will rise with the transit already in progress.

Time Zone	Eastern (EDT)	Central (CDT)	Mountain (MDT)	Pacific (PDT)
Transit start	7:12 a.m.	6:12 a.m.	5:12 a.m.	Not visible
Mid-transit	10:57 a.m.	9:57 a.m.	8:57 a.m.	7:57 a.m.
Transit end	2:42 p.m.	1:42 p.m.	12:42 p.m.	11:42 a.m.

Nov. 2006 animation by Hinode. Credit: NASA

At first glance, the planet might look like a small sunspot, but if you look closely, you’ll see it’s a small, perfectly circular black dot compared to the out-of-round sunspots which also possess the classic two-part umbra-penumbra structure. Oh yes, it also moves. Slowly to be sure, but much faster than a typical sunspot which takes nearly two weeks to cross the Sun’s face. With a little luck, a few sunspots will be in view during transit time; compared to midnight Mercury their “black” umbral cores will look deep brown.

I want to alert you to four key times to have your eye glued to the telescope; all occur during the 3 minutes and 12 seconds when Mercury enters and exits the Sun. They’re listed below in Universal Time or UT. To convert UT to EDT, subtract 4 hours; CDT 5 hours; MDT 6 hours, PDT 7 hours, AKDT 8 hours and HST 10 hours.

The black drop effect seen to good advantage during the June 2004 transit of Venus. Credit: Jan Herold

First contact (11:12 UT): Watch for the first hint of Mercury’s globe biting into the Sun just south of the due east point on along the edge of disk’s edge. It’s always a thrill to see an astronomical event forecast years ago happen at precisely the predicted time.

Second contact (11:15 UT): Three minutes and 12 seconds later, the planet’s trailing edge touches the inner limb of the Sun at second contact. Does the planet separate cleanly from the solar limb or briefly remain “connected” by a narrow, black “line”, giving the silhouette a drop-shaped appearance?

This “black drop effect” is caused primarily by diffraction, the bending and interfering of light waves when they pass through the narrow gap between Mercury and the Sun’s edge. You can replicate the effect by bringing your thumb and index finger closer and closer together against a bright backdrop. Immediately before they touch, a black arc will fill the gap between them.

The "black drop effect" can be reproduced by slowly bringing your thumb and index finger together. It's caused by diffraction combined with blurring from the atmosphere. Credit: Bob King — The “black drop effect” can be reproduced by slowly bringing your thumb and index finger together. It’s caused by diffraction combined with blurring from the atmosphere. Credit: Bob King

Third contact (18:39 UT): A minute or less before Mercury’s leading edge touches the opposite limb of the Sun at third contact, watch for the black drop effect to return.

Fourth contact (18:42 UT): The moment the last silhouetted speck of Mercury exits the Sun. Don’t forget to mark your calendar for November 11, 2019, date of the next transit, which also favors observers in the Americas and Europe. After that one, the next won’t happen till 2032.

Other interesting visuals to keep an eye out for is a bright ring or aureole that sometimes appears around the planet caused when our brain exaggerates the contrast of an object against a backdrop of a different brightness. Another spurious optical-brain effect keen-eyed observers can watch for is a central bright spot inside Mercury’s black disk. Use high power to get the best views of these obscure but fascinating phenomena seen by many observers during Mercury transits.

NASA's Hinode X-ray telescope captured this view of Mercury silhouetted against the Sun's corona during the Nov. 2006 transit. Similar views are possible in H-alpha light. Credit: NASA — NASA’s Hinode X-ray telescope captured this view of Mercury silhouetted against the Sun’s corona during the Nov. 2006 transit. Similar views are possible in H-alpha light should the planet pass in front of a prominence. Credit: NASA

While I’ve been talking all “white light” observation, the proliferation of relatively inexpensive and portable hydrogen-alpha telescopes in recent years makes them another viewing option with intriguing possibilities. These instruments show solar phenomena beyond the Sun’s limb, including the flaming prominences normally seen only during a total eclipse. That makes it possible to glimpse Mercury minutes in advance of the transit (or minutes after transit end) silhouetted against a prominence or nudging into the rim furry ring of spicules surrounding the outer limb. Wow!

One final note. Be careful never to look directly at the Sun even for a moment during the transit. Keep your eyes safe! When aiming a telescope, the safest and easiest way to center the Sun in the field of view is to shift the scope up and down and back and forth until the shadow the tube casts on the ground is shortest. Try it.

I hope the weather gods smile on you on May 9, but it they don’t or if you live where the transit won’t be visible, Italian astrophysicist Gianluca Masi will stream it live on his Virtual Telescope website starting at 11:00 UT (6 a.m CDT).

April 12, 2016 by David Dickinson

Prelude to Transit: Catching Mercury Under Dusk Skies

Mercury and the Moon — The waxing gibbous Moon passes Mercury (low to the right). Image credit and copyright: Tavi Greiner

Have you ever seen Mercury? The diminutive innermost world takes the center stage next month, as it transits the Sun as seen from our early perspective on May 9^th. This week, we’d like to turn your attention to bashful Mercury’s dusk apparition, which sets up the clockwork celestial gears for this event. Continue reading “Prelude to Transit: Catching Mercury Under Dusk Skies”

March 7, 2016March 7, 2016 by Jason Major

Dark Stains on Mercury Reveal Its Ancient Crust

Expanded-color image of Mercury's 52-km Degas crater, showing an abundance of low-reflectance material (LRM).

Ever since the MESSENGER spacecraft entered orbit around Mercury in 2011, and indeed even since Mariner 10‘s flyby in 1974, peculiar “dark spots” observed on the planet’s surface have intrigued scientists as to their composition and origin. Now, thanks to high-resolution spectral data acquired by MESSENGER during the last few months of its mission, researchers have confirmed that Mercury’s dark spots contain a form of carbon called graphite, excavated from the planet’s original, ancient crust.

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December 30, 2015April 18, 2016 by Matt Williams

How Many Moons Does Mercury Have?

Planet Mercury as seen from the MESSENGER spacecraft in 2008. Credit: NASA/JPL

Virtually every planet in the Solar System has moons. Earth has The Moon, Mars has Phobos and Deimos, and Jupiter and Saturn have 67 and 62 officially named moons, respectively. Heck, even the recently-demoted dwarf planet Pluto has five confirmed moons – Charon, Nix, Hydra, Kerberos and Styx. And even asteroids like 243 Ida may have satellites orbiting them (in this case, Dactyl). But what about Mercury?

If moons are such a common feature in the Solar System, why is it that Mercury has none? Yes, if one were to ask how many satellites the planet closest to our Sun has, that would be the short answer. But answering it more thoroughly requires that we examine the process through which other planets acquired their moons, and seeing how these apply (or fail to apply) to Mercury.

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November 11, 2015December 23, 2015 by David Dickinson

MESSENGER Spies a Meteor Shower… on Mercury

Leonid meteor storms. Taurid meteor swarms. Earth is no stranger to meteor showers, that’s for sure. Now, it turns out that the planet Mercury may experience periodic meteor showers as well.

The news of extraterrestrial meteor showers on Mercury came out of the annual Meeting of the Division of Planetary Sciences of the American Astronomical Society currently underway this week in National Harbor, Maryland. The study was carried out by Rosemary Killen of NASA’s Goddard Spaceflight Center, working with Matthew Burger of Morgan State University in Baltimore, Maryland and Apostolos Christou from the Armagh Observatory in Northern Ireland. The study looked at data from the MErcury Surface Space Environment Geochemistry and Ranging (MESSENGER) spacecraft, which orbited Mercury until late April of this year. Astronomers published the results in the September 28^th issue of Geophysical Research Letters.

Micrometeoroid debris litters the ecliptic plane, the result of millions of years of passages of comets through the inner solar system. You can see evidence of this in the band of the zodiacal light visible at dawn or dusk from a dark sky site, and the elusive counter-glow of the gegenschein.

The orbit of comet 2P Encke. Image credit: NASA/JPL

Researchers have tagged meteoroid impacts as a previous source of the tenuous exosphere tails exhibited by otherwise airless worlds such as Mercury. The impacts kick up a detectable wind of calcium particles as Mercury plows through the zodiacal cloud of debris.

“We already knew that impacts were important in producing exospheres,” says Killen in a recent NASA Goddard press release. “What we did not know was the relative importance of comet streams over zodiacal dust.”

This calcium peak, however, posed a mystery to researchers. Namely, the peak was occurring just after perihelion—Mercury orbits the Sun once every 88 Earth days, and travels from 0.31 AU from the Sun at perihelion to 0.47 AU at aphelion—versus an expected calcium peak predicted by researchers just before perihelion.

A key suspect in the calcium meteor spike dilemma came in the way of periodic Comet 2P Encke. Orbiting the Sun every 3.3 years—the shortest orbit of any known periodic comet—2P Encke has made many passages through the inner solar system, more than enough to lay down a dense and stable meteoroid debris stream over the millennia.

With an orbit ranging from a perihelion at 0.3 AU interior to Mercury’s to 4 AU, debris from Encke visits Earth as well in the form of the November Taurid Fireballs currently gracing the night skies of the Earth.

The Encke connection still presented a problem: the cometary stream is closest to the orbit of Mercury about a week later than the observed calcium peak. It was as if the stream had drifted over time…

Enter the Poynting-Robertson effect. This is a drag created by solar radiation pressure over time. The push on cometary dust grains thanks to the Poynting-Robertson effect is tiny, but it does add up over time, modifying and moving meteor streams. We see this happening in our own local meteor stream environment, as once great showers such as the late 19^th century Andromedids fade into obscurity. The gravitational influence of the planets also plays a role in the evolution of meteor shower streams as well.

Researchers in the study re-ran the model, using MESSENGER data and accounting for the Poynting-Robertson effect. They found the peak of the calcium emissions seen today are consistent with millimeter-sized grains ejected from Comet Encke about 10,000 to 20,000 years ago. That grain size and distribution is important, as bigger, more massive grains result in a smaller drag force.

A 2015 Taurid meteor. Image credit: Kevin Palmer

This finding shows the role and mechanism that cometary debris plays in exosphere production on worlds like Mercury.

“Finding that we can move the location of stream to match MESSENGER’s observations is gratifying, but the fact that the shift agrees with what we know about Encke and its stream from independent source makes us confident that the cause-and-effect relationship is real, says Christou in this week’s NASA Goddard press release.

Launched in 2004, MESSENGER arrived at Mercury in March 2011 and orbited the world for over four years, the first spacecraft to do so. MESSENGER mapped the entire surface of Mercury for the first time, and became the first human-made artifact to impact Mercury on April 30^th, 2015.

The joint JAXA/ESA mission BepiColombo is the next Mercury mission in the pipeline, set to leave Earth on 2017 for insertion into orbit around Mercury on 2024.

An interesting find on the innermost world, and a fascinating connection between Earth and Mercury via comet 2P Encke and the Taurid Fireballs.