Wednesday, August 27, 2014

Racetrack "Sailing Stones" Witnessed... Mystery Solved!

"Sailing stone" on the Racetrack, Death Valley
In one of the enduring mysteries of the world, people have long wondered how rocks move across a horizontal dry lake bed surface in Death Valley National Park.

People have offered a variety of theories on how the rocks moved, with the first scientific study in 1948 suggesting dust devils.

More recently, high winds were suggested:

Using Differential GPS to Map the "Sliding" Rocks of Racetrack Playa
"So the evidence suggests that strong gusts of wind and swirling dust devils, in combination with a slick playa surface may set even the heaviest the rocks in motion. Off they go, scooting along downwind until friction slows them down and they come to rest. There the stones wait for the next time when slippery mud and wind spur them into action again." http://www.profsurv.com/magazine/article.aspx?i=769#sthash.WI0c906F.dpuf

In 2008 Ralph Lorenz of Johns Hopkins University proposed that the rocks moved when embedded in bouyant "ice cakes", as had been witnessed in tidal areas in the arctic.
"The stones partially embedded in the floating ice rise slightly above the bottom with the increasing level of water. Both the friction between the ice and water and between the stones and the bed are very small, so that blowing wind with some intensity pushes the ice (and the rocks embedded). If the stones and mud at the bottom have a light touch, the dragged stones leave a trail that remains once the ice has melted and the water has evaporated." http://blogs.egu.eu/gsoil/2013/08/26/ladies-and-gentlemen-the-rolling-stones/

Would magically energetic rocks look like this when moving?
Having seen many of the prior theories, I offered the following explanation on April 1, 2010:
"Their secret... an internal power source!  They glow as they move.  Who knew?"

My April Fools Day theory didn't gain much traction. It was fun to illustrate though!

Fortunately there were some much more serious people working on the case, so on December 21, 2013, Richard and James Norris were present to see standing water frozen on the lake bed, and to see and hear the ice cracking as the ice started to melt, then wind blew the ice sheet with the rocks embedded.  You can read the full account in today's story in the +Los Angeles Times:

Mystery of how rocks move across Death Valley lake bed solved
http://www.latimes.com/local/lanow/la-me-ln-rocks-move-death-valley-lake-bed-20140827-story.html

I had actually predicted that mode of movement after reading an article on the stones in +National Geographic seven years ago, as I mentioned in this comment on +Flickr:
"I don't believe that 700 pound rocks can move by wind alone; I think they need to be trapped in floating ice, melting along the shore, that far outweighs them and which also catches the wind. Even the heaviest rocks are inconsequential when a solid lake surface that weighs many tons starts shifting in the wind."

I didn't exactly run up there to photograph it... Ice, high winds, while access to the area may be limited, what's not to like about that?   There are some good reasons why no one has been there to see it!


Z truth is out there...
Now that the mystery is solved, will this end the pilgrimage of people wanting to see these rocks, now that the mystery is gone?  The National Park Service worries that the news may actually increase traffic.

Will the end to the mystery stop people from stealing the rocks, with the hope that they have magical powers?

Of course not.  The proposal that the rocks don't have magical powers could simply be a government cover-up, right?  The sale of tinfoil hats to Death Valley visitors will be greater than ever.

Update 7 pm:
Here's a video which includes a sequence showing a rock moving.  Jump forward to 2:58 if you want to go straight there:

Tuesday, August 26, 2014

Plan Your Moon, Mars, Saturn Conjunction Photo August 30 & 31

Shooting the moon, Mars and Saturn over Bodie's 1937 Chevy at 9 pm, Saturday August 30, 2014
Last weekend offered the opportunity to shoot the crescent moon near Jupiter and Venus.  Now that the new moon has passed, as the crescent moon moves into the evening sky, we have the opportunity to catch the moon with Mars and Saturn on consecutive nights.  The first night will be August 30, when the moon will be roughly 11 degrees high at 9 pm (here at 38 degrees latitude) as the sky gets dark, near bright star Spica and west of the two planets.  The screen shot from +The Photographer's Ephemeris ("TPE", free on a PC) shows a possible composition shooting over the 1937 Chevy in Bodie State Historic Park.  The park closes after 6 pm, but we're bringing a group in for a night photography workshop, so the crescent moon and planet conjunction event is a nice bonus opportunity for us.

The even tighter and more interesting configuration will be on the following night August 31 when the moon joins Saturn and Mars to form a close triangle.  At 9 o'clock for mid-northern latitudes the moon will be southwest and roughly 17 degrees high, moving westward and setting over the next hour.

To plan some shots for this celestial event, you can use apps such as The Photographer's Ephemeris, +PhotoPills , StarWalk and Sky Safari+:
StarWalk Screen showing conjunction August 31
Here's a screen shot from the StarWalk app showing the relative positions of Mars, Saturn and the moon. (The appearance of them on the screen is not to scale.)  Using this app to see the relative position of the three objects, then using TPE or PhotoPills to pick natural landmarks on the horizon or man-made objects in your foreground to place them over, you can plan for some interesting compositions well in advance.  A wide shot to capture a foreground subject might work well at 14-24mm, while a telephoto composition might range from 50 mm to 200mm.  You can capture individual planets or the moon at longer focal lengths.  I may use my crop sensor Canon 70D to get an extra effective 1.6X magnification, so my 70-200 mm lens with 2X teleconverter shooting at 400 mm will produce an effective 640 mm.

Saturn over Mars (upper right)
You can scout potential locations for your shot all week, just look for the red light of Mars to the southwest as darkness falls, in the evening about an hour after sunset, and Saturn is the bright planet just to the right of Mars.  This is a location I scouted and ruled out earlier this week due in part to excessive light pollution just out of frame to the right.  Mars is the red planet in the upper right (and even easier to see in the reflection), while Saturn is just to the right.  The crescent moon between and above them will make a tight grouping, so I should bring my Canon 50 mm f/1.4 and 85 mm f/1.8 lenses to be able to use wider apertures and lower ISO settings for less noisy results.

A handy planning site for the Moon, Mars, Saturn conjunction event on August 31 tries to recognize your location to be able to give accurate times for visibility of Saturn in the evening, as well as set times for Saturn, the moon and Mars: http://in-the-sky.org/news.php?id=20140831_15_100

Photos of the Moon, Venus and Jupiter Conjunction August 23

Jupiter, moon and M44 Beehive Cluster rising yesterday, August 23.  A short while later Venus joined them, below Jupiter.
The Internet, mobile phones and social media can provide some interesting opportunities at times.  I learned about a close Venus - Jupiter conjunction coming up on August 18 from the SkyWeek+ app from +Sky & Telescope.  I looked up more information, and found an excellent planning guide by +Universe Today.  I shot the August 18 conjunction, only to have Universe today include it moments later in their write-up on the event!  I looked up more articles, discovering a mention in an +EarthSky article of the moon joining them in the sky on the morning  August 23.  But there would be a nice practice day August 22, which I shot.  As it turned out, EarthSky included my Aug 18 Venus - Jupiter image in an excellent planning guide to the August 23 event.

Venus, Jupiter, moon and Beehive Cluster in conjunction 
I checked my app The Photographer's Ephemeris to confirm a good composition for the moon rise angle at Mono Lake.  I then checked the StarWalk app and determined that the last of the three celestial bodies rising on the 23rd,Venus, would be rising at 4:53 at Mono Lake.  So I arrived onsite yesterday at around 4:30, I was moving my cameras into position around 4:45, and I was just getting my exposures settings set as the moon rose next to Jupiter and its moons (above).  Venus was the next to arrive (right), and its light was colored bright red in the atmosphere choked with smoke from fires in the American West.

Apparently no other photographers had planned to shoot here, although one car did pull in and leave its headlights on briefly, providing some unplanned light painting on the tufa-strewn shoreline.  The sky gradually brightened as twilight "blue hour" progressed, and the view of the moon became more clear and it tone more white as it rose above the densest slice of atmosphere.  Venus increased in apparent brightness as it rose, and hints of the approaching sunrise could be seen on the horizon.


Venus, Jupiter and moon during blue hour
As the planets and moon rose together, I had to zoom out to a wider 70 mm focal length to fit them in comfortably.  Incresed color in the sky was offset by the relative fading of the planets as the sky brightened.

Later this week we'll have this sort of opportunity all over again as the crescent moon yields to the new moon, then becomes a crescent again as it switches to the night sky, and moves close to Mars and Saturn.  I'll talk more on that in a following post here on my blog, and I'll post updates on Twitter (@jeffsullphoto) as well.

The moon, Jupiter and Venus as dawn approaches on August 23
Here's one of my last shots of the moon with Jupiter and Venus last Saturday as the sky continued to brighten:

Thursday, August 21, 2014

Venus Jupiter Conjunction August 18 to Add Moon August 23

Venus plus Jupiter with four of its moons before dawn August 18
Venus - Jupiter Aug 18
The Venus -  Jupiter Conjunction was a rare event to catch Monday morning before dawn, as they slowly rose above the horizon as dawn approached.  It's always great to be out in the early morning, as many animals are active and others start to stir.  Two great horned owls gently called back and forth.  Black bears have been in our neighborhood at night lately gorging on peaches, and plums, blackberries and apples are starting to add to their buffet as well.  A group of coyotes were howling in the small orchard down the street, no doubt harassing a bear getting in the way of their hunt for rabbits and quail.  It was nice to have some moonlight for illumination, so I'd be able to see a bear approaching if I heard one leaving the orchard in my direction.  I kept a flashlight nearby to alert any bears to my presence, to avoid an awkward encounter.  Being so well fed our bears are large.  They're not overtly aggressive and they'll generally run away from people, but it's still a good idea not to startle one at close range.
As the week progresses Venus and Saturn remain close all this week, with the crescent moon arriving in their vicinity on the mornings of August 22, 23 and 24. Their closest encounter will be on Saturday the 23rd, with the two planets and the moon forming a triangle before dawn, 7 degrees on each side.

Update Friday morning, August 22:  The moon lined up with Venus and Jupiter this morning.  The moon will drop next to Venus and Jupiter tomorrow morning before dawn, to form a triangle.  Venus rose today at 4:53, so for best results, start looking by 5 am.  Where I plan to shoot tomorrow, all three celestial bodies should be above the horizon by 5:10 or so.  The times will be similar for other mid northern latitudes, with small adjustments for your position on the earth and in your time zone.

Plan for an interesting composition for the conjunction tomorrow using any of these four astronomy apps:

Tutorial on Moon Photography Planning

http://activesole.blogspot.com/2013/10/tutorial-on-moon-photography-planning.html  


The rest of the story:

As I shot Venus and Jupiter this morning there were large, fresh bear prints on the ground, and half of an apple that the bear carried 1/2 mile but couldn't finish.  The bears start arriving late at night this time of year, but as they compete for fruit in neighborhood fruit trees, they start to come earlier and earlier.

This large bear climbed up a neighbor's tree last year when we arrived to take his picture.  He growled at me at first, but stopped when that tactic didn't result in our departure.  On this night, our neighbor had called us at 8 pm to tell us that there was a huge bear which "looks like a bison", his back scraping the branches of the apple trees.  He definitely was well fed, and is probably back for more feasting this year.

Wednesday, August 20, 2014

Astronomy Photographer of the Year 2014 Video Released Today

Moon Over Half Dome, Yosemite National Park
Thanks to the +Royal Observatory Greenwich in London for including my image in your video about the Astronomy Photographer of the Year 2104 competition!  Read my 2012 blog post about this image: Moon Rise over Half Dome in Yosemite


Astrophotography is a great way to encourage an interest in science and engineering among young people.  In 2011 the Royal Observatory Greenwich sent a film crew to interview my daughter +Nicole Sullivan in 2011 when she won Runner Up (2nd Place) in the Young Astronomers category of the competition.


Nicole: the blue hour from Royal Observatory Greenwich on Vimeo.


Nicole will be attending the University of California, Davis this fall, and she is considering a number of careers related to science and engineering.

"Origins of Life on Earth" image by Thomas Sullivan
Nicole's brother +Thomas Sullivan is not far from applying for college as well.  He was honored with an Honorable Mention in the 2012 Astronomy Photographer of the Year contest, and his photo appears on the cover of the Japanese edition of the coffee table book containing awarded entries in the competition, available for purchase through Amazon.com.

#astrophoto2014 #astrophotography #landscapephotography #APOTY #2014

Monday, August 18, 2014

Perseid Meteor Shower 2014 Continues as Moon Rises Later

Perseid meteor over mining ruins, Eastern Sierra
I set up my camera Friday night to take a sequence of shots so I could make a composite all of the meteors I caught in the hour before the moon rise, but I only caught this one Perseid meteor. I still made a composite photo however, since the best Milky Way was when I first set up and the meteor came later as the moon was rising, washing out the view of the Milky Way. So everything in this photo is exactly where it happened, but the 11:29 pm meteor is effectively time-shifted into this image from 10:32 pm.

Thanks to +Angela Fritz of the +Capital Weather Gang at the +Washington Post for blogging two of my earlier 2014 Perseid meteor shower photos over the weekend:
In past years I've captured time-lapse video of the Perseid meteor shower, as in the first 1:49 of this 7 minute video:

Venus - Jupiter Conjunction at Dawn Today


Venus and Jupiter put on a show in the sky this morning as sunrise approached.  As seen from earth these two bright planets appeared to pass within 0.3 degrees of each other in the sky.

For the next shot I used a crop sensor camera to get a little more effective zoom out of my lenses:
Canon 70D, 70-200mm f/4 IS L lens, 2X teleconverter
400mm focal length x 1.6 crop factor = 640mm equivalent


I uploaded one of my shots to Flickr, and +Universe Today had already blogged it moments later.  Thanks +Nancy Atkinson!
Here's a link to the blog post by Universe Today:

Monday, August 11, 2014

Perseid Meteor 2014

Perseid meteor 4:19 am August 11, 2014
Yes, it is possible to get Perseid meteors in spite of the full moon.  This one was at 4:19 am, right next to the North Star, Polaris.  For a little over 1.5 hour I had my camera shooting 15 second exposures at f/5.6, ISO 2000.  At roughly four shots per minute, I ended up with nearly 400 images.  This was by far the brightest Perseid fireball I caught.  I don't know if our clouds will break enough for me to shoot again tonight, but if they do, I may focus on a ground-based subject and see whether I can happen to pick up some meteors as well. 

To see some of my Perseid meteor shower time-lapse videos from past years, visit my YouTube account to see them in my Night Time-lapse playlist:

   #2014

Saturday, August 09, 2014

Transit of Venus in Front of the Sun, June 2012

The planet Venus (black dot) passes in front of the sun, as seen from earth
When the planet Venus was scheduled to pass in front of the sun in early June 2012 I wanted to capture the event, but I didn't want to simply record a dark spot in front of a bright one. So I decided to place earth-bound objects in front of the sun to capture the Sun, Earth and Venus in the same shot. And why not... the next opportunity to capture a Venus transit across the face of the sun wouldn't come for another 105 years!

There will a a transit of Mercury across the sun on May 9, 2016.  This article on timeanddate.com can tell you when the mercury transit may be available from your location.  It also provides links to information on proper eye protection!

"After centuries of trying, only photographic technology could measure the ‘Transit of Venus’ and tell us our position in the solar system." - +Royal Observatory Greenwich


#astrophoto2014 #astronomy #science #astrophotography

Monday, August 04, 2014

Guaranteed Delivery Photo Sharing Networks: Flickr, Instagram, Twitter


A crate originally containing blasting caps, explosive charges used to set off dynamite, sits in an abandoned house in the historic mining town of Bodie, California. 

The "handle carefully" label on the box is good advice for photographers in the fragmented world of online photography sharing world.  While other sites shelter copyright violators, invade your privacy and threaten to sell your photos without any benefit to you, Flickr remains a key place for serious photographers, arguably THE place.  But if you want to connect with friends and family on social media sites, or grow your audience with photographers who haven't found or returned to Flickr yet, you may have to spread a few of your photos around a bit.  Sites don't all connect to one another, and they have different functionality, so details can get lost from site to site, and where you share to or from can affect how well your photos are received where they end up.

Let's consider Instagram, Twitter and Flickr.  Instagram can be a receptive place for mobile phone photos, but I don't spend much time on Instagram.  I have more followers on Twitter, and Twitter is known as a place for real time updates.  But Instagram photos shared directly to Twitter don't show up with a preview image, greatly reducing the odds that anyone will see, let alone respond to, your tweet.  So if I want to make a mobile phone share to Instagram and also reach my friends who might be on Twitter, it's best to post to Instagram and Flickr at once, then from Flickr share to Twitter.  A Flickr share to Twitter does result in a photo being posted with the tweet, with a thumbnail included in the left colum, so your odds of interaction with your post are much higher.  But most importantly there's also a link back to the original photo on Flickr, a full-featured "home base" for photography.

Many sites have popped up over the years enabling sharing photos, but many of them have implemented filters preventing all of the people who have subscribed to see you photos from actually seeing them.  Flickr does not prevent other photographers from seeing your work, it does not tolerate or even facilitate copyright violators like some other sites, it hasn't had privacy issue after privacy issue, there haven't been scandals where they would allow selling of your work without your knowledge or permission, and most importantly, it remains the photography place with the strongest tagging, grouping, album, location, date and interestingness-ranking functionality, that intelligent searches can be performed on.  So when your'e going to a national park and want to get ideas on where to go and what to see at that time of year, you can perform a search and find some great images and places.  Others can similarly find your images that way.  And everyone is easily accessible, you just post a question below their photograph or send them a flickrmail, there's no weird layer of site intervention over who can "friend" whom, or which people can communicate with each other.

For this photo I took an iPhone photo and used the free Snapseed app to post-process it and post it simultaneously to Flickr and Instagram.  So technically it started here as well as there.  Then I used the Flickr to Twitter sharing function to  tweet the photo with a preview image and link back here on Flickr.  It's simple, fast, gets the photo were I need it, and lets me keep my portfolio grounded on Flickr where I can best manage it.

Where I want a more subtle and controlled edit I may wait to import my iPhone images into Lightroom and upload the edited images from my PC to Flickr.  In that case I then go to the Flickr app and I can download my Lightroom-edited photo on Flickr to my phone's camera roll storage.  Like magic, any of my photos on Flickr, even ones taken on a DSLR, can be shared to otherwise mobile-centric apps like Instagram that way.

With the strong tagging/metadata and search functionality it seems like Flickr is still one of the places editors look first to find images.  It'll be interesting to see whether the new licensing functionality announced last week can reinforce and amplify that trend.