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10 great places to see meteor showers in the US

Deep blue starry sky over dark mountains; multiple thin white streaks in the sky.

Meteors over Death Valley via Will Li/ AccuWeather.

AccuWeather originally published this article in June 2020. EarthSky editors also contributed.

Meteor showers can be a trickle, or they can be astounding natural events. Either way, these light shows give people a glimpse of the vastness of space and, in many ways, motivate people to be more in tune with nature. However, there’s one major hurdle that prevents many people from ever experiencing a meteor shower: light pollution from home and city outdoor lighting. Unless you live in a dark country location, your own backyard probably isn’t the best place to watch a meteor shower. With this in mind, here’s a list of 10 places to see the meteor showers in the U.S., recommended by AccuWeather.

Want to know when to watch? Try EarthSky’s meteor shower guide for 2020

Got a great stargazing location to recommend? Recommend here

Try EarthSky’s Best Places to Stargaze page for lots more recommended dark sites.

Note: In 2020, some public parks are closed due to Covid-19. Be sure to check with these parks first, before you go.

1. Big Bend National Park, Texas. The world’s best places to see meteor showers are going to be untouched environments, such as national parks. Big Bend National Park in far west Texas has night skies that are nothing short of magical. It’s a great place to watch a meteor shower!

Many thin white streaks in charcoal-gray sky with a beam of light from ground to sky.

View larger. | Sergio Garcia Rill caught the Perseid meteor shower in Big Bend National Park in 2015. He wrote, “Well, here’s the result of a night at the Cerro Castellan area inside Big Bend. This photo has got 23 meteors in it, as well as me trying to find some shooting stars with my flashlight.” Thank you Sergio!

2. Joshua Tree National Park, California. Given the many densely populated cities in California, it’s hard to imagine that this state would have good sites to see meteor showers. But – like all states in the United States – it does. Beloved Joshua Tree National Park is one of the places in California to see stars and meteors.

Starry sky with prominent Orion constellation and short horizontal greenish-white streak.

Joan Schipper wrote: “The Sierra Club Camera Committee went to Joshua Tree National Park trying to catch some Orionid meteors in pixels. Eight of us were staked out in various locations at White Tank campground. This is my 3rd attempt to capture meteors and my 2nd bit of success.”

3. Death Valley, California/Nevada. Don’t let its name scare you. Straddling California and Nevada, Death Valley – with its naturally dark skies – is another hot spot for meteor showers and stargazing.

Many thin, vertical white streaks in sky above dry mountain landscape.

The 2018 Geminid meteor shower rains down on Death Valley, as seen from Zabriskie Point. Comet Wirtanen is visible in the upper left, below and to the left of Pleiades. Image via Rick Whitacre.

4. Finger Lakes, New York. Much like California, New York has densely populated areas. But New York has the beauty of the Finger Lakes for people to enjoy. Because Finger Lakes are located away from the bright lights of the city, its night skies provide an incredible view.

5. The area around Tucson, Arizona. This desert region is surrounded by tall hills and mountains, places where you can get up high to look at the sky.

Several meteor trails over a desert landscape with tall cacti.

Draconids near Tucson, Arizona, in 2013, by our friend Sean Parker Photography.

6. Denali National Park, Alaska. Generally speaking, Alaska is a place many would expect to find on this list. The state is full of natural beauty. That said, Denali National Park in Alaska is known for its dark skies.

7. Brockway Mountain, Michigan. A great place for stargazing and meteor-watching in the upper midwest.

8. Big Pine Key, Florida. If Alaska is an obvious candidate for seeing meteor showers, Florida might be the opposite. Yet Big Pine Key in Florida has an annual winter party for stargazing.

Dark sky with brilliant curved white streak from ground to near zenith.

If you’re in Florida for stargazing, be sure to check with Cape Canaveral to see if there are any space launches you can watch, to add to your experience. Richard Benzinger in Crescent Beach, Florida, caught the March 16, 2017, SpaceX launch of Echostar XXIII from Cape Canaveral, shooting southeast. Thanks, Richard!

9. White Sands, New Mexico. While it is not as flat as Death Valley, White Sands is flat enough and dark enough to provide a great platform for meteor-watching.

10. Canyonlands National Park, Utah. Stargazing and meteor-watching under Utah’s glorious night skies … what could be better?

Deep purple flat-topped mesas under a starry sky.

View larger. | Quinn Pratt caught this 2014 photo of night skies over Canyonlands National Park. Thank you, Quinn!

Bottom line: Ten recommended sites for watching meteor showers, from AccuWeather and the editors of EarthSky.

Want to know when to watch meteor showers? Try EarthSky’s meteor shower guide for 2020

Got a great stargazing location to recommend? Recommend here

Try EarthSky’s Best Places to Stargaze page for lots more recommended dark sites.

from EarthSky https://ift.tt/3g3zPnw

Meteors over Death Valley via Will Li/ AccuWeather.

AccuWeather originally published this article in June 2020. EarthSky editors also contributed.

Want to know when to watch? Try EarthSky’s meteor shower guide for 2020

Got a great stargazing location to recommend? Recommend here

Try EarthSky’s Best Places to Stargaze page for lots more recommended dark sites.

Note: In 2020, some public parks are closed due to Covid-19. Be sure to check with these parks first, before you go.

The 2018 Geminid meteor shower rains down on Death Valley, as seen from Zabriskie Point. Comet Wirtanen is visible in the upper left, below and to the left of Pleiades. Image via Rick Whitacre.

5. The area around Tucson, Arizona. This desert region is surrounded by tall hills and mountains, places where you can get up high to look at the sky.

Draconids near Tucson, Arizona, in 2013, by our friend Sean Parker Photography.

7. Brockway Mountain, Michigan. A great place for stargazing and meteor-watching in the upper midwest.

8. Big Pine Key, Florida. If Alaska is an obvious candidate for seeing meteor showers, Florida might be the opposite. Yet Big Pine Key in Florida has an annual winter party for stargazing.

9. White Sands, New Mexico. While it is not as flat as Death Valley, White Sands is flat enough and dark enough to provide a great platform for meteor-watching.

10. Canyonlands National Park, Utah. Stargazing and meteor-watching under Utah’s glorious night skies … what could be better?

View larger. | Quinn Pratt caught this 2014 photo of night skies over Canyonlands National Park. Thank you, Quinn!

Bottom line: Ten recommended sites for watching meteor showers, from AccuWeather and the editors of EarthSky.

Want to know when to watch meteor showers? Try EarthSky’s meteor shower guide for 2020

Got a great stargazing location to recommend? Recommend here

Try EarthSky’s Best Places to Stargaze page for lots more recommended dark sites.

from EarthSky https://ift.tt/3g3zPnw

Asteroid Day, June 30, live from Luxembourg

Space scene with many floating rocks illuminated with light from distant sun.

Image via Debbie Lewis.

Originally published at AsteroidDay.org.

The Asteroid Foundation returns with Asteroid Day Live Digital from Luxembourg. This year, the event is a fully digital celebration of asteroid science and exploration. Panel discussions and one-on-one interviews with astronauts and world experts will be broadcast on June 30, 2020.

Asteroid Day Live is streaming over Asteroid Day TV, and the detailed program schedule can be found on the Asteroid Day website. Following Asteroid Day on June 30, the various panels will be available on that website, as well as on YouTube.

Asteroid Day is held on June 30 each year to mark the date of Earth’s largest asteroid impact in recorded history, the Siberia Tunguska event. Asteroid Day was co-founded by astrophysicist and famed musician Dr. Brian May of the rock group Queen, Apollo 9 astronaut Rusty Schweickart, filmmaker Grig Richters, and B612 Foundation President Danica Remy, to educate the public about the importance of asteroids in our history and the role they play in the solar system. In 2016, with the leadership of the Association of Space Explorers (ASE), the United Nations declared Asteroid Day to be a global day of education to raise awareness and promote knowledge in the general public about asteroids. For more information visit AsteroidDay.org.

Each year Asteroid Day presents the public with a snapshot of cutting-edge asteroid research from the largest telescopes on Earth to some of the most ambitious space missions. Topics of discussion this year include the acceleration in the rate of our asteroid discoveries and why it is set to accelerate even faster, the imminent arrival of samples from asteroid Ryugu and Bennu, the exciting preparations for the joint U.S.-Europe mission to binary asteroid Didymos, and much more.

Bright white smoke trail above bare trees in snowy landscape.

Early in the morning on February 15, 2013, a small, previously unknown asteroid entered Earth’s atmosphere at 37,280 miles per hour (66,000 km/h) and exploded high above Chelyabinsk, Russia, with 20-30 times the energy of the Hiroshima atomic bomb. Photo via Alex Alishevskikh/ Flickr.

Asteroids are the leftover remnants of the birth of the planets in the solar system, and many are the shattered fragments of these diminutive proto-planets that never made it to maturity.

Tom Jones, Ph.D., veteran astronaut and planetary scientist, and Asteroid Day Expert Panel member, said:

Asteroid exploration missions tell us about the birth of our own planet and reveal how asteroids can serve astronauts as stepping stones to Mars.

Each asteroid is an individual with its own story to tell. And that’s what Asteroid Day is all about: bringing those stories to the widest audience possible.

Ruy Pinto, Chief Technology Officer at SES, said:

Space and science have been an endless source of inspiration for SES! This is one of the reasons why we and our partners continue to do extraordinary things in space to deliver amazing experiences everywhere on earth.

Through satellite broadcasting, we are able to reach millions of TV households and this enables us to unite people around science, space, and technology topics.

Mark Serres, the CEO of the Luxembourg Space Agency, said:

The valuable expertise of SES and BCE play a central role in making Asteroid Day an international success and enabling us to have a global conversation about space, space resources, and asteroids in these COVID-19 times.

Such studies can also protect our planet. European Space Agency (ESA) Director General Jan Wörner noted:

An asteroid impact is a natural disaster we might be able to avoid if we see one coming soon enough

Join Asteroid Day Live Digital from Luxembourg to celebrate the solar system’s magnificent debris.

Asteroid Day Live Digital from Luxembourg is a five-hour program with panel discussions including:

Panel hosts include Sarah Cruddas, Alan Boyle, Lisa Burke, Sabinije von Gaffke, and Stuart Clark. The panel summary descriptions can be found here.

In the week leading up to Asteroid Day, the European Space Agency will produce several Asteroid Day programs in French, Spanish, Dutch, German, and Italian including asteroid experts and special guests discussing European planetary defense and asteroid-related activities aimed at general audiences in those countries and ESA debuts an English segment on June 30 as part of Asteroid Day LIVE from Luxembourg.

In addition to the ESA programs, there are independent online talks taking place worldwide as well. “Stones Fallen From the Sky: The Birth of the Science of Asteroids and Meteorites” will come from Spain, and Asteroid Day Chile has organized for 20+ national institutions to give talks, workshops for children, and audiovisual segments. These will be broadcast on Facebook Live and YouTube simultaneously on June 29 and 30. These and more can be found online at asteroidday.org; only a limited number of independent events are possible this year due to Covid-19.

The story of Asteroid Day.

Bottom line: The 6th annual Asteroid Day will be held as a digital event on June 30, 2020. It’ll feature presentations with experts, panel discussions, and question-and-answer periods. Here’s how to participate.

Via AsteroidDay.org

from EarthSky https://ift.tt/2KDhe65

Image via Debbie Lewis.

Originally published at AsteroidDay.org.

Asteroids are the leftover remnants of the birth of the planets in the solar system, and many are the shattered fragments of these diminutive proto-planets that never made it to maturity.

Tom Jones, Ph.D., veteran astronaut and planetary scientist, and Asteroid Day Expert Panel member, said:

Asteroid exploration missions tell us about the birth of our own planet and reveal how asteroids can serve astronauts as stepping stones to Mars.

Each asteroid is an individual with its own story to tell. And that’s what Asteroid Day is all about: bringing those stories to the widest audience possible.

Ruy Pinto, Chief Technology Officer at SES, said:

Space and science have been an endless source of inspiration for SES! This is one of the reasons why we and our partners continue to do extraordinary things in space to deliver amazing experiences everywhere on earth.

Through satellite broadcasting, we are able to reach millions of TV households and this enables us to unite people around science, space, and technology topics.

Mark Serres, the CEO of the Luxembourg Space Agency, said:

The valuable expertise of SES and BCE play a central role in making Asteroid Day an international success and enabling us to have a global conversation about space, space resources, and asteroids in these COVID-19 times.

Such studies can also protect our planet. European Space Agency (ESA) Director General Jan Wörner noted:

An asteroid impact is a natural disaster we might be able to avoid if we see one coming soon enough

Join Asteroid Day Live Digital from Luxembourg to celebrate the solar system’s magnificent debris.

Asteroid Day Live Digital from Luxembourg is a five-hour program with panel discussions including:

Panel hosts include Sarah Cruddas, Alan Boyle, Lisa Burke, Sabinije von Gaffke, and Stuart Clark. The panel summary descriptions can be found here.

The story of Asteroid Day.

Via AsteroidDay.org

from EarthSky https://ift.tt/2KDhe65

More evidence that Europa’s ocean is habitable

Light-colored terrain with many brown cracks and streaks.

Europa has many cracks in its otherwise smooth surface. Many believe the cracks are the result of the rising and falling of tides in a global ocean beneath Europa’s icy surface. A new study adds to the evidence that this subsurface ocean may be habitable. Image via NASA/ JPL-Caltech/ SETI Institute.

Is there life on Jupiter’s ocean moon Europa? This moon has fascinated space enthusiasts for decades, since scientists determined there’s a global ocean of water beneath the moon’s icy outer crust. Last week (June 24, 2020), NASA scientists announced new research that supports the idea that Europa’s ocean is habitable. They said this underground ocean is likely similar in many ways to the open-air oceans on Earth.

The fascinating results were presented at the Goldschmidt conference (virtual this year due to Covid-19). The associated abstract is available on the conference website. These are preliminary results, and not yet peer-reviewed.

First, the findings support what scientists had predicted about the composition of the ocean, as planetary scientist and lead researcher Mohit Melwani Daswani explained in a statement:

We were able to model the composition and physical properties of the core, silicate layer, and ocean. We find that different minerals lose water and volatiles at different depths and temperatures. We added up these volatiles that are estimated to have been lost from the interior, and found that they are consistent with the current ocean’s predicted mass, meaning that they are probably present in the ocean.

Layers of water and ice with jets coming up through the ice, with a huge banded sphere and small sphere in black background.

A cutaway illustrative view of Europa’s subsurface ocean. Image via NASA/ JPL-Caltech/ Sci-News.

To reach this conclusion, the researchers modeled geochemical reservoirs within the interior of Europa using data from the old Galileo mission. The results are significant since they show that oceans like the one on Europa can be formed by metamorphism, that is, by a change of minerals or a distinct arrangement of minerals (a change in what geologists call texture) in preexisting rocks (protoliths) without the protolith melting into liquid magma.

On Europa, heating and increased pressure caused by early radioactive decay or later subsurface tidal movement, would have caused a breakdown of water-containing minerals. Trapped water would be released, and Europa’s underground ocean would be born.

So what about habitability?

The study also found that Europa’s ocean would have been mildly acidic at first, with high concentrations of carbon dioxide, calcium and sulfate. But over time, it became chloride-rich, resembling oceans on Earth (seawater on Earth contains 1.94% chloride). According to Daswani:

Indeed it was thought that this ocean could still be rather sulfuric, but our simulations, coupled with data from the Hubble Space Telescope, showing chloride on Europa’s surface, suggests that the water most likely became chloride rich. In other words, its composition became more like oceans on Earth. We believe that this ocean could be quite habitable for life.

Europa is one of our best chances of finding life in our own solar system. NASA’s Europa Clipper mission will launch in the next few years, and so our work aims to prepare for the mission, which will investigate Europa’s habitability. Our models lead us to think that the oceans in other moons, such as Europa’s neighbor Ganymede, and Saturn’s moon Titan, may also have formed by similar processes.

We still need to understand several points though, such as how fluids migrate through Europa’s rocky interior.

Billowing geyser-like plume on icy terrain with large planet and distant sun in the sky.

Although not proven yet, there is growing evidence for water vapor plumes on Europa, similar to those on Saturn’s moon Enceladus (artist’s concept). Image via ASA/ ESA/ K. Retherford/ SwRI/ Science.

Another interesting possibility is that volcanic vents on the seafloor of Europa’s ocean might have contributed to the process of the water’s becoming chloride-rich. That would be exciting, since such vents on Earth provide heat and nutrients to a wide variety of life in our world’s deep oceans.

The Cassini spacecraft has already found evidence for such vents on the seafloor of Saturn’s moon Enceladus, which also has a global ocean beneath its icy crust.

These or other energy sources would be necessary for life to evolve and thrive in an underground ocean: a dark and sunless environment. As Steve Mojzsis, Professor of Geology at the University of Colorado Boulder, noted:

A long-standing question over whether a ‘cloaked ocean’ world like Europa could be habitable boils down to whether it can sustain a flow of electrons which might provide the energy to power life. What remains unclear is whether such icy moons could ever generate enough heat to melt rock; certainly interesting chemistry takes place within these bodies, but what reliable flow of electrons could be used by alien life to power itself in the cold, dark depths?

A key aspect that makes a world ‘habitable’ is an intrinsic ability to maintain these chemical disequilibria. Arguably, icy moons lack this ability, so this needs to be tested on any future mission to Europa.

Illuminated white-ish sphere covered with many thin brown streaks, on black background.

Jupiter’s ocean moon Europa, as seen by the Galileo spacecraft. This image is a combination of images from 1995 and 1998. Image via NASA/ JPL-Caltech/ SETI Institute.

The results of the new study are tantalizing, but more work needs to be done. How much chloride is really in Europa’s ocean? As mentioned in a June 25, 2020, article on Centauri Dreams, a paper from 2019 stated the following about sodium chloride (NaCl) on Europa:

The presence of NaCl on Europa has important implications for our understanding of the internal chemistry and its geochemical evolution through time. Whereas aqueous differentiation of chondritic material and long-term leaching from a chondritic seafloor can result in a system rich in sulfates, more extensive hydrothermal circulation, as on Earth, may lead to an NaCl-rich ocean. The plume chemistry of Enceladus, which is perhaps the best analog to Europa, suggests an NaCl-dominated ocean and a hydrothermally active seafloor. However, the compositional relationship between Europa’s ocean and its endogenous material is unknown, and the surface may simply represent the end result of a compositional stratification within the ice shell… Regardless of whether the observed NaCl directly relates to the ocean composition, its presence warrants a reevaluation of our understanding of the geochemistry of Europa.

Scientists can learn more about Europa’s ocean by modeling, but obtaining solid evidence will require actually sending a mission back there. Fortunately, NASA’s Europa Clipper mission is set to do just that, scheduled to launch in 2023.

Europa is one of the largest moons in the solar system with a diameter of 1,926 miles (3,100 km), just a little less than Earth’s moon. While the subsurface ocean is relatively warm (exact temperature not known yet), on the almost airless surface of Europa the temperatures are always a bitter minus 256 degrees Fahrenheit (minus 160 degrees Celsius) or lower.

Smiling man with beard and eyeglasses, with bridge in background.

Mohit Melwani Daswani, planetary scientist at NASA and lead author of the new study. Image via Jet Propulsion Laboratory (JPL).

There is also growing evidence for water vapor plumes on Europa, similar to those on Saturn’s moon Enceladus. If they are there, Europa Clipper could fly through them, just as Cassini did at Enceladus, and sample the vapor for analysis. If connected to the ocean, as Enceladus’ are thought to be, that would provide valuable clues as to conditions in the Europan ocean and, maybe, even evidence of life itself.

The latest analysis of Europa’s ocean is tantalizing, but we will know a lot more after Europa Clipper – and ESA’s Jupiter Icy Moon Explorer (JUICE) mission – take a closer look in the years ahead.

Bottom line: New study by NASA scientists shows that Europa’s ocean is habitable.

Source: Evolution of volatiles from Europa’s interior into its ocean

Via Astrobiology Web

from EarthSky https://ift.tt/2AanyhM

First, the findings support what scientists had predicted about the composition of the ocean, as planetary scientist and lead researcher Mohit Melwani Daswani explained in a statement:

We were able to model the composition and physical properties of the core, silicate layer, and ocean. We find that different minerals lose water and volatiles at different depths and temperatures. We added up these volatiles that are estimated to have been lost from the interior, and found that they are consistent with the current ocean’s predicted mass, meaning that they are probably present in the ocean.

A cutaway illustrative view of Europa’s subsurface ocean. Image via NASA/ JPL-Caltech/ Sci-News.

So what about habitability?

Indeed it was thought that this ocean could still be rather sulfuric, but our simulations, coupled with data from the Hubble Space Telescope, showing chloride on Europa’s surface, suggests that the water most likely became chloride rich. In other words, its composition became more like oceans on Earth. We believe that this ocean could be quite habitable for life.

Europa is one of our best chances of finding life in our own solar system. NASA’s Europa Clipper mission will launch in the next few years, and so our work aims to prepare for the mission, which will investigate Europa’s habitability. Our models lead us to think that the oceans in other moons, such as Europa’s neighbor Ganymede, and Saturn’s moon Titan, may also have formed by similar processes.

We still need to understand several points though, such as how fluids migrate through Europa’s rocky interior.

The Cassini spacecraft has already found evidence for such vents on the seafloor of Saturn’s moon Enceladus, which also has a global ocean beneath its icy crust.

A long-standing question over whether a ‘cloaked ocean’ world like Europa could be habitable boils down to whether it can sustain a flow of electrons which might provide the energy to power life. What remains unclear is whether such icy moons could ever generate enough heat to melt rock; certainly interesting chemistry takes place within these bodies, but what reliable flow of electrons could be used by alien life to power itself in the cold, dark depths?

A key aspect that makes a world ‘habitable’ is an intrinsic ability to maintain these chemical disequilibria. Arguably, icy moons lack this ability, so this needs to be tested on any future mission to Europa.

Jupiter’s ocean moon Europa, as seen by the Galileo spacecraft. This image is a combination of images from 1995 and 1998. Image via NASA/ JPL-Caltech/ SETI Institute.

The presence of NaCl on Europa has important implications for our understanding of the internal chemistry and its geochemical evolution through time. Whereas aqueous differentiation of chondritic material and long-term leaching from a chondritic seafloor can result in a system rich in sulfates, more extensive hydrothermal circulation, as on Earth, may lead to an NaCl-rich ocean. The plume chemistry of Enceladus, which is perhaps the best analog to Europa, suggests an NaCl-dominated ocean and a hydrothermally active seafloor. However, the compositional relationship between Europa’s ocean and its endogenous material is unknown, and the surface may simply represent the end result of a compositional stratification within the ice shell… Regardless of whether the observed NaCl directly relates to the ocean composition, its presence warrants a reevaluation of our understanding of the geochemistry of Europa.

Mohit Melwani Daswani, planetary scientist at NASA and lead author of the new study. Image via Jet Propulsion Laboratory (JPL).

Bottom line: New study by NASA scientists shows that Europa’s ocean is habitable.

Source: Evolution of volatiles from Europa’s interior into its ocean

Via Astrobiology Web

from EarthSky https://ift.tt/2AanyhM

2 lunar perigees in June 2020

Above: A simulation of the moon’s phase on June 29-30, 2020, as our companion world reaches its second lunar perigee of this month. The image is via Fourmilab.

The moon in its orbit swings closest to Earth at perigee, and farthest away from Earth at apogee. There are a total of 13 lunar perigees in 2020, so it’s inevitable that one calendar month this year has to harbor two lunar perigees. That double feature happens in June 2020. Depending on where you live worldwide, the second of two June 2020 perigees falls on June 29 or 30 (June 30 at 2:09 UTC). A playful person might wish to call this a Blue Moon perigee, given the popular definition of Blue Moons as the second full moon of a month, and given that this June 29-30 perigee is the second of two lunar perigees this month.

How to catch the elusive green flash

The green flash image at the top of this post was taken by Chris Mannerino, from SanDiego, California, USA, on December 13, 2017.

It’s not hard to see a green flash with the eye alone, when sky conditions are right, and when you’re looking toward a very clear and very distant horizon. That’s why those who live near an ocean tend to report green flashes most often. A sea horizon is the best place to see them.

The video below, posted to EarthSky by Vladek in 2016, is an excellent example of the experience of seeing a green flash:

Most people see green flashes just at sunset, at the last moment before the sun disappears below the horizon. Be careful and don’t look too soon. If you do look too soon, the light of the sunset will dazzle (or damage) your eyes, and you’ll miss your green flash chance that day. But if you wait – looking away until just the thinnest rim of the sun appears above the horizon – that day’s green flash could be yours.

Of course, the green flash can be seen before sunrise, too, although it’s harder at that time of day to know precisely when to look.

Pyramid-like deep orange setting sun with green smudge at top.

Mock mirage and green flash seen from San Francisco in 2006. Image via Brocken Inaglory/Wikimedia Commons.

There are many different types of green flash. Some describe a streak or ray of the color green … like a green flame shooting up from the sunrise or sunset horizon.

The most common green flash, though – the one most people describe – is a flash of the color green seen when the sun is nearly entirely below the horizon.

Again … you need a distant horizon to see any of these phenomena, and you need a distinct edge to the horizon. That’s why these green flashes, streaks, and rays are most often seen over the ocean. But you can see them over land, too, if your horizon is far enough away. Pollution or haze on the horizon will hide this instantaneous flash of the color green.

Orange sky, blue sea, tugboat silhouette with green smudge on horizon.

Jim Grant photographed this green flash on April 27, 2012, off the coast of San Diego.

If you’re interested in green flashes, Andrew Young’s green flash page is great. He also has a page of links to pictures of green flashes taken by people from around the globe.

And, of course, Les Cowley at the great website Atmospheric Optics devotes many pages to the green flash phenomenon. Notice the menu bar at the left side of the page; it’ll let you explore many different types of green flashes.

Yellow pyramid with tall tower silhouetted in center and bright green top.

Green flash atop sun pyramid via astrophotographer Colin Legg in Australia.

Bottom line: The green flash is legendary, and some people have told us they thought it was a myth, like a unicorn or a pot of gold at the end of a rainbow. But green flashes are very real. You need a distant and exceedingly clear horizon to see them at the last moment before the sun disappears below the horizon at sunset.

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Old moon and morning planets on April 17, 2020.

Are you an early riser? Then catch the old moon beneath the line-up of three bright morning planets: Jupiter, Saturn and Mars.

Can you see a green flash? More tips, plus more pictures

from EarthSky https://ift.tt/3i7qHQB

The green flash image at the top of this post was taken by Chris Mannerino, from SanDiego, California, USA, on December 13, 2017.

The video below, posted to EarthSky by Vladek in 2016, is an excellent example of the experience of seeing a green flash:

Of course, the green flash can be seen before sunrise, too, although it’s harder at that time of day to know precisely when to look.

Mock mirage and green flash seen from San Francisco in 2006. Image via Brocken Inaglory/Wikimedia Commons.

There are many different types of green flash. Some describe a streak or ray of the color green … like a green flame shooting up from the sunrise or sunset horizon.

The most common green flash, though – the one most people describe – is a flash of the color green seen when the sun is nearly entirely below the horizon.

Jim Grant photographed this green flash on April 27, 2012, off the coast of San Diego.

If you’re interested in green flashes, Andrew Young’s green flash page is great. He also has a page of links to pictures of green flashes taken by people from around the globe.

Green flash atop sun pyramid via astrophotographer Colin Legg in Australia.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Are you an early riser? Then catch the old moon beneath the line-up of three bright morning planets: Jupiter, Saturn and Mars.

Can you see a green flash? More tips, plus more pictures

from EarthSky https://ift.tt/3i7qHQB

News digest – targeted drug approval, microbubble ‘warheads’ and prostate cancer treatment

With news about the coronavirus pandemic developing daily, we want to make sure everyone affected by cancer gets the information they need during this time.

We’re pulling together the latest government and NHS health updates from across the UK in a separate blog post, which we’re updating regularly.

Targeted drug to treat multiple cancer types approved in England

A targeted cancer drug has been approved for NHS use in England to treat multiple cancer types, reports The Times and Mail Online. Entrectinib is designed to target specific changes in a cancer cell’s DNA, rather than where the cancer is growing in the body. It’s the second drug of its kind to be approved for NHS use in England, after larotrectinib was given the green light in April this year. These innovative treatments have been hailed as ‘revolutionary, but they also post unique and complex challenges for the NHS, as our blog post explains.

Targeted drug improves survival for children with non-Hodgkin lymphoma

New clinical trial results show that adding rituximab to standard chemotherapy could improve survival for children and young people with a fast-growing type of non-Hodgkin lymphoma. The results have been called “the most significant breakthrough in treating this type of cancer for 30 years”. Our news report has the story.

New targeted cancer drug safe in early clinical trials

BBC News reports on early trials of a new drug that could stop cancer cells repairing their DNA. Initial trials of borzosertib, involving 40 people with advanced cancers, found the drug was well tolerated by patients. Researchers also saw early indications that the treatment was having an effect on tumour growth, but as the study was not designed to measure the effectiveness of the treatment, it’s too early to talk about the drug’s benefits.

Prostate cancer drug rejected for NHS use in England

A hormone therapy for some adults with newly, diagnosed, advanced prostate cancer has been rejected by the National Institute of Health and Care Excellence. Clinical trial data suggests that abiraterone improves survival compared to some current treatment options, but NICE raised concerns that the drug’s effective had been overestimated. Our news report has the story.

Lower activity levels associated with increased risk of cancer death

A new study of over 8,000 adults has found a link between those who don’t move for long periods of time and an increased risk of dying from cancer. By monitoring participants using wearable tracking devices, researchers found that the most sedentary participants had an 82% higher risk of dying from the disease, taking into account factors such as age, gender and disease status. Read more on this at Insider.

‘Starved’ cancer cells more sensitive to chemotherapy

Researchers at Lund University in Sweden have succeeded in making acute myeloid leukaemia cells more sensitive to chemotherapy in the lab by blocking sugar uptake. Scientists have tried to target cancer’s altered metabolism for many years, with mixed success. Full story at Lund University.

And finally…

A new ultrasound technique could be harnessed to kill cancer cells. During the experimental study, researchers used ultrasound to trigger microbubbles to explode, creating a targeted ‘warhead’. The team found that by directly injecting the microbubbles into tumours in mice, and then applying a low frequency ultrasound, they were able to wipe out a large number of the cancer cells. But to stop any remaining cancer cells from spreading, they had to combine the microbubble treatment with an immune-boosting gene therapy. New Atlas has this one.

Scarlett Sangster is a writer for PA Media Group

from Cancer Research UK – Science blog https://ift.tt/3i64Bhf

With news about the coronavirus pandemic developing daily, we want to make sure everyone affected by cancer gets the information they need during this time.

We’re pulling together the latest government and NHS health updates from across the UK in a separate blog post, which we’re updating regularly.

Targeted drug to treat multiple cancer types approved in England

Targeted drug improves survival for children with non-Hodgkin lymphoma

New targeted cancer drug safe in early clinical trials

Prostate cancer drug rejected for NHS use in England

Lower activity levels associated with increased risk of cancer death

‘Starved’ cancer cells more sensitive to chemotherapy

And finally…

Scarlett Sangster is a writer for PA Media Group

from Cancer Research UK – Science blog https://ift.tt/3i64Bhf

Latest sunsets follow summer solstice

Image at top: Peter Gipson in Stowmarket, Suffolk, England, captured this June sunset, complete with a sun pillar. Thanks, Peter! Submit your image to EarthSky here.

For people living around 40 degrees north latitude, the latest sunset of the year happens on or near June 27. And in the Southern Hemisphere, at 40 degrees south latitude, it’s the year’s latest sunrise that happens around now. That’s in spite of the fact that the Northern Hemisphere’s longest (or Southern Hemisphere’s shortest) day of the year fell on the June 20 solstice.

The year’s latest sunset always comes after the summer solstice, even though the exact date of the latest sunset depends on your latitude. Farther north – at Seattle – the latest sunset happened around June 25. Farther south – at Mexico City or Hawaii – the latest sunset won’t happen until early July.

Want to know your date of latest sunset? Try this custom sunrise/sunset calendar.

Perspective view of dark clouds over bright sunset, long pier running toward horizon.

June sunset – Pere Marquette Beach in Muskegon, Michigan – via Jerry James Photography. Thank you, Jerry!

The latest sunset comes after the summer solstice because the day is more than 24 hours long at this time of the year.

For several weeks, around the June solstice, the day (as measured by successive returns of the midday sun) is nearly 1/4 minute longer than 24 hours. Hence, the midday sun (solar noon) comes later by the clock in late June than it does on the June solstice. Therefore, the sunrise and sunset times also come later by the clock, as the table below helps to explain.

For Denver, Colorado

Date	Sunrise	Midday (Solar Noon)	Sunset	Daylight Hours
June 20	5:32 a.m.	1:01 p.m.	8:31 p.m.	14h 59m 15s
June 27	5:33 a.m.	1:03 p.m.	8:32 p.m.	14h 57m 50s

Source: timeanddate.com

Dark trees each side, colors yellow to orange to lavender to blue in sky.

Juan Argudin in Pembroke Pines, Florida, wrote on June 21, 2018: “We’ve taken dozens of sunset pictures but cannot remember such beautiful sunset colors. This was the first sunset after summer solstice, taken between 2 live oak trees in front of our house. Thank you for your excellent newsletter. We have learned a lot.” Photo by Olga Argudin. Thank you, Juan and Olga!

If the Earth’s axis stood upright as our world circled the sun, and if, in addition, the Earth stayed the same distance from the sun all year long, then clock time and sun time would always agree. However, the Earth’s axis is titled 23.44 degrees out of vertical, and our distance from the sun varies by about 3 million miles (5 million km) throughout the year. At and around the equinoxes, solar days are shorter than 24 hours, yet at the solstices, solar days are longer than 24 hours.

The latest sunset always comes on or near June 27 at mid-northern latitudes every year.

At mid-northern latitudes, the later clock time for solar noon one week after the summer solstice is more substantial than the change in daylight hours. Given that the daylight hours today (June 27) are almost the same as they were a week ago (on the June 20th solstice), the later clock time for today’s solar noon gives us slightly later sunrise and sunset times, as well

Bottom line: Why don’t the latest sunsets come on the longest day (the solstice)? In a nutshell, it’s a discrepancy between the sun and the clock. Thus, for mid-northern latitudes, the latest sunsets always come in late June.

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Image at top: Peter Gipson in Stowmarket, Suffolk, England, captured this June sunset, complete with a sun pillar. Thanks, Peter! Submit your image to EarthSky here.

Want to know your date of latest sunset? Try this custom sunrise/sunset calendar.

June sunset – Pere Marquette Beach in Muskegon, Michigan – via Jerry James Photography. Thank you, Jerry!

The latest sunset comes after the summer solstice because the day is more than 24 hours long at this time of the year.

For Denver, Colorado

Date	Sunrise	Midday (Solar Noon)	Sunset	Daylight Hours
June 20	5:32 a.m.	1:01 p.m.	8:31 p.m.	14h 59m 15s
June 27	5:33 a.m.	1:03 p.m.	8:32 p.m.	14h 57m 50s

Source: timeanddate.com

The latest sunset always comes on or near June 27 at mid-northern latitudes every year.

Enjoying EarthSky so far? Sign up for our free daily newsletter

Donate: Your support means the world to us

from EarthSky https://ift.tt/2KHCZSn