Leo loses his tail. We gain a constellation

Tonight’s chart shows the sky in April high to the south around mid-evening. To the upper left of the constellation Leo the Lion are dozens of very faint stars. They make up the constellation Coma Berenices, otherwise known as Berenice’s Hair. You need a dark sky to appreciate the constellation Coma Berenices. If you have one … it’s very beautiful.

The Greek-Egyptian astronomer Ptolemy and others considered these stars the tuft at the end of Leo the Lion’s tail. Coma Berenices remained part of Leo until a few hundred years ago, when it was first listed as a separate constellation.

The story goes that an ancient Egyptian queen, Berenice, feared for her husband’s life as he went into battle. She prayed to Aphrodite, promising to cut off her long, luxurious curls if the king returned safely. He did, and Berenice kept her promise and cut off her hair, placing it as a sacrifice on Aphrodite’s altar.

But the next day the hair was gone!

The constellation Coma Berenices. Click here for a larger sky chart

The king was enraged that the temple priests had not protected the precious locks. A quick-thinking astronomer saved the day, or rather night, by pointing to the cascading stars at the end of Leo’s tail. He told the king that these were the queen’s tresses placed in the sky by Aphrodite for all to see.

The king and queen were appeased, and no priests were beheaded.

There’s a vast cluster of galaxies located in the direction of the constellation Coma Berenices. Here is a majestic face-on spiral galaxy located deep within the Coma Cluster. Read more about the Coma galaxy cluster. Image via NASA

Bottom line: The constellation Leo once had a tail, a clump of faint stars. Now these same stars are known as Coma Berenices, the hair of a queen.

Star-hop from Leo to the Coma star cluster

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

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

Tonight’s chart shows the sky in April high to the south around mid-evening. To the upper left of the constellation Leo the Lion are dozens of very faint stars. They make up the constellation Coma Berenices, otherwise known as Berenice’s Hair. You need a dark sky to appreciate the constellation Coma Berenices. If you have one … it’s very beautiful.

The Greek-Egyptian astronomer Ptolemy and others considered these stars the tuft at the end of Leo the Lion’s tail. Coma Berenices remained part of Leo until a few hundred years ago, when it was first listed as a separate constellation.

The story goes that an ancient Egyptian queen, Berenice, feared for her husband’s life as he went into battle. She prayed to Aphrodite, promising to cut off her long, luxurious curls if the king returned safely. He did, and Berenice kept her promise and cut off her hair, placing it as a sacrifice on Aphrodite’s altar.

But the next day the hair was gone!

The constellation Coma Berenices. Click here for a larger sky chart

The king was enraged that the temple priests had not protected the precious locks. A quick-thinking astronomer saved the day, or rather night, by pointing to the cascading stars at the end of Leo’s tail. He told the king that these were the queen’s tresses placed in the sky by Aphrodite for all to see.

The king and queen were appeased, and no priests were beheaded.

There’s a vast cluster of galaxies located in the direction of the constellation Coma Berenices. Here is a majestic face-on spiral galaxy located deep within the Coma Cluster. Read more about the Coma galaxy cluster. Image via NASA

Bottom line: The constellation Leo once had a tail, a clump of faint stars. Now these same stars are known as Coma Berenices, the hair of a queen.

Star-hop from Leo to the Coma star cluster

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

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

Protecting oil companies instead of the climate-vulnerable is elitist

This is a re-post from the Bulletin of the Atomic Scientists

At a recent House congressional hearing on legislation aimed at addressing homelessness, Rep. Sean Duffy, a Wisconsin Republican, introduced an amendment aimed at demonstrating how addressing climate change could increase the cost of housing. In the hearing Duffy said, “We talk about how we care about the poor, but all the while we’ll sign bills that dramatically increase the cost of a family to get into a home” during his criticism of the cost of a Green New Deal. He continued:  “…[R]ich, wealthy elites who will look at this and go, ‘I love it, because I’ve got big money in the bank; everyone should do this. We should all sign onto it.’ But if you’re a poor family, just trying to make ends meet, it’s a horrible idea.”

The great irony is that poor families are the most vulnerable to the impacts of climate change. They have the fewest resources available to adapt or recover when struck by a climate-amplified hurricane or wildfire or flood. One study found that nearly half of the low-income parents affected by Hurricane Katrina experienced post-traumatic stress disorder. Poorer developing countries are also the most vulnerable to climate change because of their lack of resources and because they tend to be nearer the equator where temperatures are already hot. Research has shown that countries with more temperate climates like the United States and Europe are near the peak temperature for economic activity. Poorer tropical countries are already hotter than optimal, so additional warming hits them particularly hard.

Surveys have also shown that minorities in America are more concerned about climate change and more supportive of climate policies, likely in part because they are more likely to live in close proximity to coal power plants. Poorer households living near these sources of air and water pollution would directly benefit from climate policies that accelerate the transition away from dirty fossil fuels toward clean energy. And as Rep. Alexandria Ocasio-Cortez, a New York Democrat, noted in her viral response to Duffy, millions of Puerto Ricans were severely impacted and thousands killed by Hurricane Maria. A year-and-a-half later, the island is still struggling to recover and is now facing a food stamp crisis.

Calling climate policy efforts “elitist” is thus completely backwards, especially when considering that opposition to such policies mostly benefits oil companies, many of which are among the most profitable in the world.

That said, there are valid concerns about the financial impacts of climate policies on lower income households. Policies such as a tax on carbon pollution would raise energy prices, and lower-income households spend a relatively large percentage of their incomes on energy. A smart climate policy should take these effects into account.

For example, the Energy Innovation and Carbon Dividend Act would offset the effects of a carbon tax by rebating the revenue equally to all American households. Because wealthier individuals have a bigger carbon footprint and because the revenue would be rebated equally to all Americans, a study of the bill’s impacts found that it would generate net revenue for 86 percent of the poorest households, whose dividend checks would be larger than their increased energy costs.

It would make sense for Republicans to flock to this free-market, small government solution that helps low-income Americans and modestly stimulates job creation and the economy. Yet of the 250 Republican members of the House and Senate in the current Congress, only one has co-sponsored the bill (alongside 25 Democrats).

One Republican out of 250.

Some Republican legislators have opted to propose their own climate policy ideas. Rep. Matt Gaetz, a Florida Republican, is drafting a so-called “Green Real Deal” that calls for investing in carbon capture and storage, renewable and nuclear energy, modernizing the electric grid, eliminating energy regulations, and expanding tax incentives for energy efficiency upgrades. There are some good ideas in the proposal—which coincidentally could be incorporated into a Green New Deal—but it does not include any specific temperature or emissions targets, or a price on carbon pollution. Senator Lamar Alexander, a Tennessee Republican called for “a New Manhattan Project for Clean Energy” that similarly would involve investment in energy research.

However, as the National Journal reported, conservatives with the White House’s ear on energy issues immediately shot down both proposals. Thomas Pyle, one of Trump’s transition advisers, argued that they would lead to “large federal budgets and the federal government picking winners and losers.” Indeed, most Republican lawmakers would not support an expansion of energy research spending, and the Trump administration’s proposed budgets have consistently aimed to cut these kinds of programs. Other Republican leaders like Senator Mike Lee of Utah have made a mockery of the whole climate policy debate, arguing that the solution is to “have some kids.”

Click here to read the rest

from Skeptical Science https://ift.tt/2FNQtqL

This is a re-post from the Bulletin of the Atomic Scientists

At a recent House congressional hearing on legislation aimed at addressing homelessness, Rep. Sean Duffy, a Wisconsin Republican, introduced an amendment aimed at demonstrating how addressing climate change could increase the cost of housing. In the hearing Duffy said, “We talk about how we care about the poor, but all the while we’ll sign bills that dramatically increase the cost of a family to get into a home” during his criticism of the cost of a Green New Deal. He continued:  “…[R]ich, wealthy elites who will look at this and go, ‘I love it, because I’ve got big money in the bank; everyone should do this. We should all sign onto it.’ But if you’re a poor family, just trying to make ends meet, it’s a horrible idea.”

The great irony is that poor families are the most vulnerable to the impacts of climate change. They have the fewest resources available to adapt or recover when struck by a climate-amplified hurricane or wildfire or flood. One study found that nearly half of the low-income parents affected by Hurricane Katrina experienced post-traumatic stress disorder. Poorer developing countries are also the most vulnerable to climate change because of their lack of resources and because they tend to be nearer the equator where temperatures are already hot. Research has shown that countries with more temperate climates like the United States and Europe are near the peak temperature for economic activity. Poorer tropical countries are already hotter than optimal, so additional warming hits them particularly hard.

Surveys have also shown that minorities in America are more concerned about climate change and more supportive of climate policies, likely in part because they are more likely to live in close proximity to coal power plants. Poorer households living near these sources of air and water pollution would directly benefit from climate policies that accelerate the transition away from dirty fossil fuels toward clean energy. And as Rep. Alexandria Ocasio-Cortez, a New York Democrat, noted in her viral response to Duffy, millions of Puerto Ricans were severely impacted and thousands killed by Hurricane Maria. A year-and-a-half later, the island is still struggling to recover and is now facing a food stamp crisis.

Calling climate policy efforts “elitist” is thus completely backwards, especially when considering that opposition to such policies mostly benefits oil companies, many of which are among the most profitable in the world.

That said, there are valid concerns about the financial impacts of climate policies on lower income households. Policies such as a tax on carbon pollution would raise energy prices, and lower-income households spend a relatively large percentage of their incomes on energy. A smart climate policy should take these effects into account.

For example, the Energy Innovation and Carbon Dividend Act would offset the effects of a carbon tax by rebating the revenue equally to all American households. Because wealthier individuals have a bigger carbon footprint and because the revenue would be rebated equally to all Americans, a study of the bill’s impacts found that it would generate net revenue for 86 percent of the poorest households, whose dividend checks would be larger than their increased energy costs.

It would make sense for Republicans to flock to this free-market, small government solution that helps low-income Americans and modestly stimulates job creation and the economy. Yet of the 250 Republican members of the House and Senate in the current Congress, only one has co-sponsored the bill (alongside 25 Democrats).

One Republican out of 250.

Some Republican legislators have opted to propose their own climate policy ideas. Rep. Matt Gaetz, a Florida Republican, is drafting a so-called “Green Real Deal” that calls for investing in carbon capture and storage, renewable and nuclear energy, modernizing the electric grid, eliminating energy regulations, and expanding tax incentives for energy efficiency upgrades. There are some good ideas in the proposal—which coincidentally could be incorporated into a Green New Deal—but it does not include any specific temperature or emissions targets, or a price on carbon pollution. Senator Lamar Alexander, a Tennessee Republican called for “a New Manhattan Project for Clean Energy” that similarly would involve investment in energy research.

However, as the National Journal reported, conservatives with the White House’s ear on energy issues immediately shot down both proposals. Thomas Pyle, one of Trump’s transition advisers, argued that they would lead to “large federal budgets and the federal government picking winners and losers.” Indeed, most Republican lawmakers would not support an expansion of energy research spending, and the Trump administration’s proposed budgets have consistently aimed to cut these kinds of programs. Other Republican leaders like Senator Mike Lee of Utah have made a mockery of the whole climate policy debate, arguing that the solution is to “have some kids.”

Click here to read the rest

from Skeptical Science https://ift.tt/2FNQtqL

Eppendorf & Science Prize for Neurobiology Entries Accepted Until June 15, 2019

Eppendorf & Science Prize for Neurobiology Entries Accepted Until June 15, 2019

Researchers 35 years and younger, the annual Eppendorf &Science Prize for Neurobiology, which is awarded for contributions to neurobiological research based on methods of molecular and cell biology, is now open for entries.

Applying requires a 1,000-word essay and tell the prize committee about your work.

The prize is $25,000 plus Science magazine will publish an essay about your work. You'll have travel paid to the Prize Ceremony held in conjunction with the Annual Meeting of the Society for Neuroscience in the USA and AAAS throws in a 10-year AAAS membership (but only a digital subscription to the magazine).

The application deadline is June 15, 2019. Apply here.

hank_campbell Wed, 04/03/2019 - 10:38

Categories

Brain and Behavior

from ScienceBlogs - Where the world discusses science https://ift.tt/2K6X6tE

Eppendorf & Science Prize for Neurobiology Entries Accepted Until June 15, 2019

Researchers 35 years and younger, the annual Eppendorf &Science Prize for Neurobiology, which is awarded for contributions to neurobiological research based on methods of molecular and cell biology, is now open for entries.

Applying requires a 1,000-word essay and tell the prize committee about your work.

The prize is $25,000 plus Science magazine will publish an essay about your work. You'll have travel paid to the Prize Ceremony held in conjunction with the Annual Meeting of the Society for Neuroscience in the USA and AAAS throws in a 10-year AAAS membership (but only a digital subscription to the magazine).

The application deadline is June 15, 2019. Apply here.

hank_campbell Wed, 04/03/2019 - 10:38

Categories

Brain and Behavior

from ScienceBlogs - Where the world discusses science https://ift.tt/2K6X6tE

Did deep groundwater cause these mysterious dark streaks on Mars?

The long, thin dark streaks on the steep walls of this Martian crater are called “recurring slope lineae” by scientists. New research suggests they originate from deep groundwater. A collection of many additional images is available on the HiRISE website. Image via Mars Reconnaissance Orbiter/NASA/JPL/University of Arizona/Lujendra Ojha et al./Geophysical Research Letters.

Modern day observations of Mars – from decades of spacecraft exploration – show that its surface is very dry today, although Mars does have ice at its poles and below its surface. However, it’s widely believed Mars once had a lot of water, including rivers, lakes and maybe even oceans. Now, scientists from the USC Arid Climates and Water Research Center have presented tentative evidence for liquid water on Mars – pockets of groundwater deep below the surface in near-equatorial regions of the planet. The peer-reviewed study was published on March 28, 2019, in Nature Geoscience.

The new paper suggests that deep groundwater might be the cause of the unusual and mysterious long, dark streaks – called recurring slope lineae by scientists – seen on steep slopes of some Martian craters and canyons. Some scientists think they are created by small, brief flows of briny water. The recurring slope lineae aren’t permanent features; they tend to occur during warmer summer months in or near equatorial regions and then fade again when it’s colder. They’ve been observed to recur in the same locations in multiple years, hence the name.

Recurring slope lineae (RSL) on the walls of Newton Crater, imaged by Mars Reconnaissance Orbiter on May 30, 2011. Image via NASA/JPL-Caltech/University of Arizona.

The study suggests that recurring slope lineae in those regions are created by deep groundwater that comes up to the surface through tectonic and impact-related fractures in the ground. Other hypotheses have said these features might be caused by melting snows, shallow subsurface water flows closer to the surface, deliquescence or dry flows of sand/dust. According to USC research scientist Essam Heggy:

We suggest that this may not be true. We propose an alternative hypothesis that they originate from a deep pressurized groundwater source which comes to the surface moving upward along ground cracks.

The idea is that cracks in the surface in some craters allow water springs or aquifers deep below the surface – perhaps starting at some 2,500 feet (750 meters) – to rise up to the surface as a result of pressure. This water then leaks onto the surface, creating the sharp and distinct linear features found on the walls of some craters and canyons, including Valles Marineris, the Grand Canyon of Mars.

As also noted by co-author Abotalib Zaki:

The experience we gained from our research in desert hydrology was the cornerstone in reaching this conclusion. We have seen the same mechanisms in the North African Sahara and in the Arabian Peninsula, and it helped us explore the same mechanism on Mars.

The mysterious recurring slope lineae on Mars tend to cluster in the planet’s equatorial regions, where temperatures are the warmest. They disappear again when the weather cools. Image via Alfred S. McEwen et al./Nature GeoScience.

In 2018, researchers at the European Space Agency (ESA) announced that they had other evidence for liquid water: the tentative discovery of a large subsurface lake near Mars’ south polar cap. ESA’s Mars Express orbiter used ground-penetrating radar – the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument (MARSIS) – to detect the suspected lake below several layers of ice and dust. The ice deposit extends down about a mile (1.5 km). Beneath that deposit, radar images showed a bright spot within one 12-mile-wide (20-km-wide) region – indicative of liquid water, not just ice. From the paper:

The presence of liquid water at the base of the Martian polar caps has long been suspected but not observed. We surveyed the Planum Australe region using the MARSIS instrument, a low-frequency radar on the Mars Express spacecraft. Radar profiles collected between May 2012 and December 2015 contain evidence of liquid water trapped below the ice of the South Polar Layered Deposits. Anomalously bright subsurface reflections are evident within a well-defined, 20-kilometer-wide [12.5-mile-wide] zone centered at 193°E, 81°S, which is surrounded by much less reflective areas. Quantitative analysis of the radar signals shows that this bright feature has [characteristics matching] that of water-bearing materials.

We interpret this feature as a stable body of liquid water on Mars.

Similar lakes have been found below thick ice at the Earth’s poles, such as Lake Vostok in Antarctica.

First-ever liquid water lake discovered on Mars? The bright horizontal feature in this image represents Mars’ icy surface. The south polar layered deposits – layers of ice and dust – are seen to a depth of about a mile (1.5 km). Below is a base layer that in some areas is even brighter than the surface reflections, highlighted in blue. Analysis of the reflected signals suggests liquid water. Image via ESA/NASA/JPL/ASI/Univ. Rome; R. Orosei et al. 2018.

Finding groundwater on Mars today would help scientists better understand how Mars evolved over billions of years, and how similar that evolution was to Earth, as explained by Heggy:

Understanding how groundwater has formed on Mars, where it is today and how it is moving helps us constrain ambiguities on the evolution of climatic conditions on Mars for the last three billion years and how these conditions formed this groundwater system. It helps us to understand the similarities to our own planet and if we are going through the same climate evolution and the same path that Mars is going. Understanding Mars’ evolution is crucial for understanding our own Earth’s long-term evolution and groundwater is a key element in this process.

Groundwater is strong evidence for the past similarity between Mars and Earth – it suggests they have a similar evolution, to some extent.

Such depth requires us to consider more deep-probing techniques to look for the source of this groundwater versus looking for shallow sources of water.

Location of previous subsurface lake near Mars’ south pole (blue spot in the square), discovered by Mars Express in 2018. Image via USGS AstrogeologyScience Center/Arizona State University/INAF.

Evidence for a current body of subsurface liquid water near Mars’ south pole is exciting, but additional such lakes closer to the equator even more so, if they can be confirmed. They would increase the chances that some kind of life – even if likely just microbes – might exist deep underground on Mars, usually thought to be the most likely place to search anyway, given the hostile conditions on Mars’ surface. In regards to the south polar lake, Jeffery Plaut at NASA’s Jet Propulsion Laboratory in California noted in New Scientist that:

If the result is confirmed, it would be the largest known occurrence of present-day liquid water on Mars. It clearly has implications for the history of climate and the possibility of habitats suitable for life.

Bottom line: Does the cold desert world Mars have underground lakes? We still don’t know for certain, but this new paper from USC – in addition to the previous south polar discovery – provides more evidence that seems to say, yes.

Source: A deep groundwater origin for recurring slope lineae on Mars

Via USC News

Via Phys.org

from EarthSky https://ift.tt/2K0WlSJ

The long, thin dark streaks on the steep walls of this Martian crater are called “recurring slope lineae” by scientists. New research suggests they originate from deep groundwater. A collection of many additional images is available on the HiRISE website. Image via Mars Reconnaissance Orbiter/NASA/JPL/University of Arizona/Lujendra Ojha et al./Geophysical Research Letters.

Modern day observations of Mars – from decades of spacecraft exploration – show that its surface is very dry today, although Mars does have ice at its poles and below its surface. However, it’s widely believed Mars once had a lot of water, including rivers, lakes and maybe even oceans. Now, scientists from the USC Arid Climates and Water Research Center have presented tentative evidence for liquid water on Mars – pockets of groundwater deep below the surface in near-equatorial regions of the planet. The peer-reviewed study was published on March 28, 2019, in Nature Geoscience.

The new paper suggests that deep groundwater might be the cause of the unusual and mysterious long, dark streaks – called recurring slope lineae by scientists – seen on steep slopes of some Martian craters and canyons. Some scientists think they are created by small, brief flows of briny water. The recurring slope lineae aren’t permanent features; they tend to occur during warmer summer months in or near equatorial regions and then fade again when it’s colder. They’ve been observed to recur in the same locations in multiple years, hence the name.

Recurring slope lineae (RSL) on the walls of Newton Crater, imaged by Mars Reconnaissance Orbiter on May 30, 2011. Image via NASA/JPL-Caltech/University of Arizona.

The study suggests that recurring slope lineae in those regions are created by deep groundwater that comes up to the surface through tectonic and impact-related fractures in the ground. Other hypotheses have said these features might be caused by melting snows, shallow subsurface water flows closer to the surface, deliquescence or dry flows of sand/dust. According to USC research scientist Essam Heggy:

We suggest that this may not be true. We propose an alternative hypothesis that they originate from a deep pressurized groundwater source which comes to the surface moving upward along ground cracks.

The idea is that cracks in the surface in some craters allow water springs or aquifers deep below the surface – perhaps starting at some 2,500 feet (750 meters) – to rise up to the surface as a result of pressure. This water then leaks onto the surface, creating the sharp and distinct linear features found on the walls of some craters and canyons, including Valles Marineris, the Grand Canyon of Mars.

As also noted by co-author Abotalib Zaki:

The experience we gained from our research in desert hydrology was the cornerstone in reaching this conclusion. We have seen the same mechanisms in the North African Sahara and in the Arabian Peninsula, and it helped us explore the same mechanism on Mars.

The mysterious recurring slope lineae on Mars tend to cluster in the planet’s equatorial regions, where temperatures are the warmest. They disappear again when the weather cools. Image via Alfred S. McEwen et al./Nature GeoScience.

In 2018, researchers at the European Space Agency (ESA) announced that they had other evidence for liquid water: the tentative discovery of a large subsurface lake near Mars’ south polar cap. ESA’s Mars Express orbiter used ground-penetrating radar – the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument (MARSIS) – to detect the suspected lake below several layers of ice and dust. The ice deposit extends down about a mile (1.5 km). Beneath that deposit, radar images showed a bright spot within one 12-mile-wide (20-km-wide) region – indicative of liquid water, not just ice. From the paper:

The presence of liquid water at the base of the Martian polar caps has long been suspected but not observed. We surveyed the Planum Australe region using the MARSIS instrument, a low-frequency radar on the Mars Express spacecraft. Radar profiles collected between May 2012 and December 2015 contain evidence of liquid water trapped below the ice of the South Polar Layered Deposits. Anomalously bright subsurface reflections are evident within a well-defined, 20-kilometer-wide [12.5-mile-wide] zone centered at 193°E, 81°S, which is surrounded by much less reflective areas. Quantitative analysis of the radar signals shows that this bright feature has [characteristics matching] that of water-bearing materials.

We interpret this feature as a stable body of liquid water on Mars.

Similar lakes have been found below thick ice at the Earth’s poles, such as Lake Vostok in Antarctica.

First-ever liquid water lake discovered on Mars? The bright horizontal feature in this image represents Mars’ icy surface. The south polar layered deposits – layers of ice and dust – are seen to a depth of about a mile (1.5 km). Below is a base layer that in some areas is even brighter than the surface reflections, highlighted in blue. Analysis of the reflected signals suggests liquid water. Image via ESA/NASA/JPL/ASI/Univ. Rome; R. Orosei et al. 2018.

Finding groundwater on Mars today would help scientists better understand how Mars evolved over billions of years, and how similar that evolution was to Earth, as explained by Heggy:

Understanding how groundwater has formed on Mars, where it is today and how it is moving helps us constrain ambiguities on the evolution of climatic conditions on Mars for the last three billion years and how these conditions formed this groundwater system. It helps us to understand the similarities to our own planet and if we are going through the same climate evolution and the same path that Mars is going. Understanding Mars’ evolution is crucial for understanding our own Earth’s long-term evolution and groundwater is a key element in this process.

Groundwater is strong evidence for the past similarity between Mars and Earth – it suggests they have a similar evolution, to some extent.

Such depth requires us to consider more deep-probing techniques to look for the source of this groundwater versus looking for shallow sources of water.

Location of previous subsurface lake near Mars’ south pole (blue spot in the square), discovered by Mars Express in 2018. Image via USGS AstrogeologyScience Center/Arizona State University/INAF.

Evidence for a current body of subsurface liquid water near Mars’ south pole is exciting, but additional such lakes closer to the equator even more so, if they can be confirmed. They would increase the chances that some kind of life – even if likely just microbes – might exist deep underground on Mars, usually thought to be the most likely place to search anyway, given the hostile conditions on Mars’ surface. In regards to the south polar lake, Jeffery Plaut at NASA’s Jet Propulsion Laboratory in California noted in New Scientist that:

If the result is confirmed, it would be the largest known occurrence of present-day liquid water on Mars. It clearly has implications for the history of climate and the possibility of habitats suitable for life.

Bottom line: Does the cold desert world Mars have underground lakes? We still don’t know for certain, but this new paper from USC – in addition to the previous south polar discovery – provides more evidence that seems to say, yes.

Source: A deep groundwater origin for recurring slope lineae on Mars

Via USC News

Via Phys.org

from EarthSky https://ift.tt/2K0WlSJ

What makes famous Blood Falls red?

Blood Falls sitting at the terminus of Taylor Glacier, spilling its bright red discharge onto Lake Bonney. Image via German Aerospace Center DLR/Flickr.

This article is republished with permission from GlacierHub. This post was written by Arley Titzler.

Amid Antarctica’s vast stretches of glittering white snow and ethereal blue glacier ice is the famous Blood Falls. Situated at the terminus of Taylor Glacier in the McMurdo Dry Valleys, Blood Falls, which is an iron-rich, hypersaline discharge, spews bold streaks of bright-red brine from within the glacier out onto the ice-covered surface of Lake Bonney.

Australian geologist Griffith Taylor was the first explorer to happen upon Blood Falls in 1911, during one of the earliest Antarctic expeditions. At the time, Taylor (incorrectly) attributed the color to the presence of red algae. The cause of this color was shrouded in mystery for nearly a century, but we now know that the iron-rich liquid turns red when it breaches the surface and oxidizes––the same process that gives iron a reddish hue when it rusts.

The discharge from Blood Falls is the subject of a new study, published February 2, 2019, in the Journal of Geophysical Research: Biogeosciences, Researchers sought to discern the origin, chemical composition, and life-sustaining capabilities of this subglacial brine. According to lead author W. Berry Lyons of The Ohio State University and his co-researchers:

The brine is of marine origin that has been extensively altered by rock-water interactions.

Researchers used to believe that Taylor Glacier was frozen solid from the surface to its bed. But as measuring techniques have advanced over time, scientists have been able to detect huge amounts of hypersaline liquid water at temperatures that are below freezing underneath the glacier. The large quantities of salt in hypersaline water enable the water to remain in liquid form, even below zero degrees Celsius [32 degrees Fahrenheit].

Overhead view of the IceMole, as it gradually descends into Taylor Glacier, melting ice as it goes. Image via German Aerospace Center DLR/Flickr.

Seeking to expand on this recent discovery, Lyons and his co-researchers conducted the first direct sampling of brine from Taylor Glacier using the IceMole. The IceMole is an autonomous research probe that clears a path by melting the ice that surrounds it, collecting samples along the way. In this study, the researchers sent the IceMole through 56 feet (17 meters) of ice to reach the brine beneath Taylor Glacier.

The brine samples were analyzed to obtain information on its geochemical makeup, including ion concentrations, salinity, and other dissolved solids. Based on the observed concentrations of dissolved nitrogen, phosphorus, and carbon, the researchers concluded that Taylor Glacier’s subglacial environment has, along with high iron and sulfate concentrations, active microbiological processes – in other words, the environment could support life.

To determine the origin and evolution of Taylor Glacier’s subglacial brine, Lyons and his co-researchers pondered other studies’ conclusions in comparison to their results. They decided the most plausible explanation was that the subglacial brine came from an ancient time period when Taylor Valley was likely flooded by seawater, though they did not settle on an exact time estimate.

An aerial view of Taylor Glacier and the location of Blood Falls. Image via Wikimedia Commons.

In addition, they found that the brine’s chemical composition was much different than that of modern seawater. This suggested that as the brine was transported throughout the glacial environment over time, weathering contributed to significant alterations in the chemical composition of the water.

This study provides insights not only for subglacial environments on Earth but also potentially to other bodies within our solar system. Seven bodies, including Titan (one of Jupiter’s moons), Enceladus and Europa (two of Saturn’s moons), Pluto and Mars are thought to harbor sub-cryospheric oceans.

Lyons and his co-researchers concluded that this subglacial brine environment likely is conducive to life. The ability of sub-cryospheric environments such as this one to support life on Earth hints at an increased possibility of finding life in similar environments elsewhere in our solar system.

Bottom line: A new study reveals why Antarctica’s Blood Falls is red.

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

Blood Falls sitting at the terminus of Taylor Glacier, spilling its bright red discharge onto Lake Bonney. Image via German Aerospace Center DLR/Flickr.

This article is republished with permission from GlacierHub. This post was written by Arley Titzler.

Amid Antarctica’s vast stretches of glittering white snow and ethereal blue glacier ice is the famous Blood Falls. Situated at the terminus of Taylor Glacier in the McMurdo Dry Valleys, Blood Falls, which is an iron-rich, hypersaline discharge, spews bold streaks of bright-red brine from within the glacier out onto the ice-covered surface of Lake Bonney.

Australian geologist Griffith Taylor was the first explorer to happen upon Blood Falls in 1911, during one of the earliest Antarctic expeditions. At the time, Taylor (incorrectly) attributed the color to the presence of red algae. The cause of this color was shrouded in mystery for nearly a century, but we now know that the iron-rich liquid turns red when it breaches the surface and oxidizes––the same process that gives iron a reddish hue when it rusts.

The discharge from Blood Falls is the subject of a new study, published February 2, 2019, in the Journal of Geophysical Research: Biogeosciences, Researchers sought to discern the origin, chemical composition, and life-sustaining capabilities of this subglacial brine. According to lead author W. Berry Lyons of The Ohio State University and his co-researchers:

The brine is of marine origin that has been extensively altered by rock-water interactions.

Researchers used to believe that Taylor Glacier was frozen solid from the surface to its bed. But as measuring techniques have advanced over time, scientists have been able to detect huge amounts of hypersaline liquid water at temperatures that are below freezing underneath the glacier. The large quantities of salt in hypersaline water enable the water to remain in liquid form, even below zero degrees Celsius [32 degrees Fahrenheit].

Overhead view of the IceMole, as it gradually descends into Taylor Glacier, melting ice as it goes. Image via German Aerospace Center DLR/Flickr.

Seeking to expand on this recent discovery, Lyons and his co-researchers conducted the first direct sampling of brine from Taylor Glacier using the IceMole. The IceMole is an autonomous research probe that clears a path by melting the ice that surrounds it, collecting samples along the way. In this study, the researchers sent the IceMole through 56 feet (17 meters) of ice to reach the brine beneath Taylor Glacier.

The brine samples were analyzed to obtain information on its geochemical makeup, including ion concentrations, salinity, and other dissolved solids. Based on the observed concentrations of dissolved nitrogen, phosphorus, and carbon, the researchers concluded that Taylor Glacier’s subglacial environment has, along with high iron and sulfate concentrations, active microbiological processes – in other words, the environment could support life.

To determine the origin and evolution of Taylor Glacier’s subglacial brine, Lyons and his co-researchers pondered other studies’ conclusions in comparison to their results. They decided the most plausible explanation was that the subglacial brine came from an ancient time period when Taylor Valley was likely flooded by seawater, though they did not settle on an exact time estimate.

An aerial view of Taylor Glacier and the location of Blood Falls. Image via Wikimedia Commons.

In addition, they found that the brine’s chemical composition was much different than that of modern seawater. This suggested that as the brine was transported throughout the glacial environment over time, weathering contributed to significant alterations in the chemical composition of the water.

This study provides insights not only for subglacial environments on Earth but also potentially to other bodies within our solar system. Seven bodies, including Titan (one of Jupiter’s moons), Enceladus and Europa (two of Saturn’s moons), Pluto and Mars are thought to harbor sub-cryospheric oceans.

Lyons and his co-researchers concluded that this subglacial brine environment likely is conducive to life. The ability of sub-cryospheric environments such as this one to support life on Earth hints at an increased possibility of finding life in similar environments elsewhere in our solar system.

Bottom line: A new study reveals why Antarctica’s Blood Falls is red.

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Star-hop to the Coma star cluster

Our chart at the top of this post shows the constellation Leo the Lion highest up for the night at roughly 9 to 10 p.m. local time (10 to 11 p.m. local daylight saving time). That’s the time on your clock no matter where you are on the globe.

Long ago, the Coma star cluster represented the Lion’s tufted tail. It is a beautiful cluster, well worth taking the time to pick out in the night sky. You can see Leo from the suburbs, but you’ll need a dark sky to find the cluster. In mid-evening now, as seen from mid-northern latitudes in the Northern Hemisphere, the constellation of the Lion will be high in the southern sky. You’ll see the Lion at nightfall, too, though more in the south-southeastern portion of sky.

An imaginary line drawn between the pointer stars in the Big Dipper - the two outer stars in the Dipper's bowl - points in one direction toward Polaris, the North Star, and in the opposite direction toward Leo.

We’ll talk more about the star cluster shortly, but first here’s how to spot Leo. Notice the chart above. A line between the two outer stars in the Bowl of the Big Dipper always points toward Leo. Two distinctive star patterns make the Lion fairly easy to identify. Leo’s brightest star – the sparkling blue-white gem Regulus – marks the bottom of a backward question mark of stars known as The Sickle. A triangle of stars highlights the Lion’s hindquarters and tail. If you see a Lion in this pattern of stars, the Sickle outlines the Lion’s mane. The triangle, meanwhile, marks the back side of Leo. Denebola, the name of the outermost star in this rear triangle of Leo, is an Arabic term meaning the Lion’s Tail.

Leo? Here’s your constellation

EarthSky Facebook friend Zhean Peter Nacionales in the Philippines captured this view of the Coma star cluster in April 2013. He wrote, “I learned at the EarthSky page to star-hop from Leo to the Coma star cluster, so I packed up my camera and tripod. It was worth it. I definitely saw this star cluster.” Thank you, Zhean!

Now let’s try star-hopping from Leo the Lion to the Coma star cluster. Nowadays, this part of the sky belongs to another constellation, Coma Berenices or Berenice’s Hair. As shown on the chart at the top of this post, or in the photo above from Zhean Peter Nacionales, you can draw a line from the star Regulus through the top star of the triangle (Zosma), and go about twice this distance to locate the cluster.

The Coma star cluster is also called Melotte 111. It’s visible to the unaided eye in a dark country sky, sparkling against the background of the Milky Way. You might need binoculars to see this loose tangle of stars if your skies are beset by light pollution. It is a beautiful sight in a dark sky.

This is an open star cluster. That means its stars were probably born together from a single cloud of gas and dust in space, and they are still loosely bound by gravity. There are about 100 stars in the Coma star cluster, which lies some 288 light-years distant. In other words, this star cluster lies within our Milky Way galaxy.

Coma star cluster in the direction of our constellation Coma Berenices. It is an open star cluster, whose member stars are thought to be loosely bound by gravity. Image via NASA/Expedition 6.

A majestic face-on spiral galaxy located deep within the Coma Cluster of galaxies. Image via NASA.

But wait. There’s more in this direction of space: a vast collection of galaxies external to our Milky Way.

The Coma galaxy cluster, also in the direction of the constellation Coma Berenices, is made up not of individual stars, but of whole galaxies of stars.

It is invisible to the unaided eye (or even in a small telescope), but astronomers with large telescopes study this region of space to learn more about the cosmos.

Coma Cluster: Galaxies in Coma Berenices

Bottom line: On springtime evenings, star-hop from the constellation Leo to the Coma star cluster in the constellation Coma Berenices. Plus – although you cannot see it with your eye or with binoculars – a huge cluster of external galaxies lies in the direction of Coma Berenices.

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky planisphere today.

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

Our chart at the top of this post shows the constellation Leo the Lion highest up for the night at roughly 9 to 10 p.m. local time (10 to 11 p.m. local daylight saving time). That’s the time on your clock no matter where you are on the globe.

Long ago, the Coma star cluster represented the Lion’s tufted tail. It is a beautiful cluster, well worth taking the time to pick out in the night sky. You can see Leo from the suburbs, but you’ll need a dark sky to find the cluster. In mid-evening now, as seen from mid-northern latitudes in the Northern Hemisphere, the constellation of the Lion will be high in the southern sky. You’ll see the Lion at nightfall, too, though more in the south-southeastern portion of sky.

An imaginary line drawn between the pointer stars in the Big Dipper - the two outer stars in the Dipper's bowl - points in one direction toward Polaris, the North Star, and in the opposite direction toward Leo.

We’ll talk more about the star cluster shortly, but first here’s how to spot Leo. Notice the chart above. A line between the two outer stars in the Bowl of the Big Dipper always points toward Leo. Two distinctive star patterns make the Lion fairly easy to identify. Leo’s brightest star – the sparkling blue-white gem Regulus – marks the bottom of a backward question mark of stars known as The Sickle. A triangle of stars highlights the Lion’s hindquarters and tail. If you see a Lion in this pattern of stars, the Sickle outlines the Lion’s mane. The triangle, meanwhile, marks the back side of Leo. Denebola, the name of the outermost star in this rear triangle of Leo, is an Arabic term meaning the Lion’s Tail.

Leo? Here’s your constellation

EarthSky Facebook friend Zhean Peter Nacionales in the Philippines captured this view of the Coma star cluster in April 2013. He wrote, “I learned at the EarthSky page to star-hop from Leo to the Coma star cluster, so I packed up my camera and tripod. It was worth it. I definitely saw this star cluster.” Thank you, Zhean!

Now let’s try star-hopping from Leo the Lion to the Coma star cluster. Nowadays, this part of the sky belongs to another constellation, Coma Berenices or Berenice’s Hair. As shown on the chart at the top of this post, or in the photo above from Zhean Peter Nacionales, you can draw a line from the star Regulus through the top star of the triangle (Zosma), and go about twice this distance to locate the cluster.

The Coma star cluster is also called Melotte 111. It’s visible to the unaided eye in a dark country sky, sparkling against the background of the Milky Way. You might need binoculars to see this loose tangle of stars if your skies are beset by light pollution. It is a beautiful sight in a dark sky.

This is an open star cluster. That means its stars were probably born together from a single cloud of gas and dust in space, and they are still loosely bound by gravity. There are about 100 stars in the Coma star cluster, which lies some 288 light-years distant. In other words, this star cluster lies within our Milky Way galaxy.

Coma star cluster in the direction of our constellation Coma Berenices. It is an open star cluster, whose member stars are thought to be loosely bound by gravity. Image via NASA/Expedition 6.

A majestic face-on spiral galaxy located deep within the Coma Cluster of galaxies. Image via NASA.

But wait. There’s more in this direction of space: a vast collection of galaxies external to our Milky Way.

The Coma galaxy cluster, also in the direction of the constellation Coma Berenices, is made up not of individual stars, but of whole galaxies of stars.

It is invisible to the unaided eye (or even in a small telescope), but astronomers with large telescopes study this region of space to learn more about the cosmos.

Coma Cluster: Galaxies in Coma Berenices

Bottom line: On springtime evenings, star-hop from the constellation Leo to the Coma star cluster in the constellation Coma Berenices. Plus – although you cannot see it with your eye or with binoculars – a huge cluster of external galaxies lies in the direction of Coma Berenices.

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky planisphere today.

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

See it! Mars meets the Sisters

View at EarthSky Community Photos. | Dennis Chabot in Rehoboth, Massachusetts – of POSNE NightSky – caught Mars and the Pleiades on April 1, 2019. Thank you, Dennis!

View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines caught Mars and the Pleiades on March 30, 2019.

View at EarthSky Community Photos. | Steven Sweet in Mississauga, Ontario, Canada – of Lunar 101 Moon Book – caught Mars and the Pleiades on March 25, 2019. Thank you, Steven.

View at EarthSky Community Photos. | Dr. Ski also caught Mars and the Pleiades on March 25, 2019. Notice the Pleiades are shjaped like a tiny dipper. And notice Mars is red in color. Now notice the V-shaped cluster of stars above them. In skylore, these stars represent the Pleiades half-sisters, called the Hyades. Thanks, Dr. Ski!

Bottom line: Photos from the EarthSky Community of Mars and the Pleiades, or Seven Sisters, in late March and early April, 2019.

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

View at EarthSky Community Photos. | Dennis Chabot in Rehoboth, Massachusetts – of POSNE NightSky – caught Mars and the Pleiades on April 1, 2019. Thank you, Dennis!

View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines caught Mars and the Pleiades on March 30, 2019.

View at EarthSky Community Photos. | Steven Sweet in Mississauga, Ontario, Canada – of Lunar 101 Moon Book – caught Mars and the Pleiades on March 25, 2019. Thank you, Steven.

View at EarthSky Community Photos. | Dr. Ski also caught Mars and the Pleiades on March 25, 2019. Notice the Pleiades are shjaped like a tiny dipper. And notice Mars is red in color. Now notice the V-shaped cluster of stars above them. In skylore, these stars represent the Pleiades half-sisters, called the Hyades. Thanks, Dr. Ski!

Bottom line: Photos from the EarthSky Community of Mars and the Pleiades, or Seven Sisters, in late March and early April, 2019.

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