The European Space Agency has a spacecraft orbiting Mars called Mars Express. One of its sensors is a ground penetrating radar that can look beneath the surface of the planet. Depending on how the radar signal is reflected, scientists can develop a good picture of what lies beneath the surface.
Now ESA reports that a radar reflection from beneath the Martian Southern Polar Ice Cap indicates the probable presence of liquid water. Where we have found liquid water on Earth, we have found life. The surface of Mars is currently inhospitable to life. However, the subsurface should be more hospitable than the surface. If life existed on Mars in the past, it may have been able to evolve to do well beneath the surface and still thrive today.
We just need to drill one mile into the surface to find out.
Here's a link to the ESA announcement, http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Mars_Express_detects_liquid_water_hidden_under_planet_s_south_pole
Wednesday, July 25, 2018
Tuesday, July 24, 2018
Idaho Skies Transcript for August 3rd, 4th, and 5th
RACHEL
Welcome to Idaho Skies for August 3rd, 4th, and 5th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The nights are warm and the meteors are plentiful.
PAUL
That’s because July and August has a large share of meteor showers.
RACHEL
The meteors stargazers see during the summer originated from comets.
PAUL
That’s because as comets approach the sun, the sun’s light warms their cold surfaces.
RACHEL
However, there’s no air in space, so the ices don’t melt into a liquid.
PAUL
Instead, the ices sublimate into a gas just as dry does on your table.
RACHEL
The gas jets carry dust particles away from the comet’s icy surface, or nucleus.
PAUL
And that dust remains in the same orbit as the comet.
RACHEL
Astronomers call those dust motes meteoroids.
PAUL
It’s when Earth’s motion intersect the orbit of meteoroids that we get to see a meteor shower.
RACHEL
Meteoroids are small; some in fact are only the size of a grain of rice.
PAUL
So they have very low mass.
RACHEL
But they’re traveling through the rarefied air at hypersonic speeds.
PAUL
Which means they have tremendous amounts of kinetic energy.
RACHEL
And that lets them create a powerful shock wave ahead of the dust grain.
PAUL
The shock waves created by hypersonic meteoroids glow white hot.
RACHEL
And that heat radiates back into the meteoroid to roast and melt it.
PAUL
Which causes most meteoroids to vaporize some 60 to 80 miles above the ground.
RACHEL
Our eyes are not sensitive or fast enough to see the glowing meteoroid or shock wave.
PAUL
Instead, we see a moving streak of light that we call a meteor.
RACHEL
If a meteoroid originates from an asteroid, than it can be large enough to survive its passage through the atmosphere.
PAUL
Then we call that surviving rock a meteorite.
RACHEL
But if it’s really an Earth rock and not a meteorite, then we call it a meteor-wrong.
PAUL
That’s Idaho Skies for the 3rd, 4th, and 5th of August.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.
For Idaho Skies this is Rachel...
PAUL
...and Paul.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for August 3rd, 4th, and 5th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The nights are warm and the meteors are plentiful.
PAUL
That’s because July and August has a large share of meteor showers.
RACHEL
The meteors stargazers see during the summer originated from comets.
PAUL
That’s because as comets approach the sun, the sun’s light warms their cold surfaces.
RACHEL
However, there’s no air in space, so the ices don’t melt into a liquid.
PAUL
Instead, the ices sublimate into a gas just as dry does on your table.
RACHEL
The gas jets carry dust particles away from the comet’s icy surface, or nucleus.
PAUL
And that dust remains in the same orbit as the comet.
RACHEL
Astronomers call those dust motes meteoroids.
PAUL
It’s when Earth’s motion intersect the orbit of meteoroids that we get to see a meteor shower.
RACHEL
Meteoroids are small; some in fact are only the size of a grain of rice.
PAUL
So they have very low mass.
RACHEL
But they’re traveling through the rarefied air at hypersonic speeds.
PAUL
Which means they have tremendous amounts of kinetic energy.
RACHEL
And that lets them create a powerful shock wave ahead of the dust grain.
PAUL
The shock waves created by hypersonic meteoroids glow white hot.
RACHEL
And that heat radiates back into the meteoroid to roast and melt it.
PAUL
Which causes most meteoroids to vaporize some 60 to 80 miles above the ground.
RACHEL
Our eyes are not sensitive or fast enough to see the glowing meteoroid or shock wave.
PAUL
Instead, we see a moving streak of light that we call a meteor.
RACHEL
If a meteoroid originates from an asteroid, than it can be large enough to survive its passage through the atmosphere.
PAUL
Then we call that surviving rock a meteorite.
RACHEL
But if it’s really an Earth rock and not a meteorite, then we call it a meteor-wrong.
PAUL
That’s Idaho Skies for the 3rd, 4th, and 5th of August.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.
For Idaho Skies this is Rachel...
PAUL
...and Paul.
RACHEL
Dark skies and bright stars.
Idaho Skies Transcript for August 1st and 2nd
PAUL
Welcome to Idaho Skies for August 1st and 2nd. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Stargazers will have noticed that Venus is getting ever closer to the horizon.
RACHEL
This means it’s on it way out of the evening sky.
PAUL
In fact, within six weeks Venus will be lost in the sun’s glare.
RACHEL
So take some time out this evening to look for Venus in the low west.
PAUL
Guess whose birthday it is on the 1st.
RACHEL
It’s the birthday of Maria Mitchell.
PAUL
Did you known that she was the first American woman to become an official astronomer?
RACHEL
One reason why is that she was born a Quaker.
PAUL
The Quaker (faith) religion is famous for viewing men and women as equals.
RACHEL
Which meant she had access to a better education than most women did in 1818.
PAUL
Maria became famous in 1847 when she discovered a comet.
RACHEL
Her comet was too faint for a person to see without a telescope.
PAUL
This made her only the third woman to discover a comet.
RACHEL
And the only American woman to do so.
PAUL
She made measurements of the comet’s position and used that data to calculate its orbit a month later.
RACHEL
Maria’s discovery and work resulted in her being awarded a gold medal by the king of Denmark.
PAUL
One result of this award is that it helped legitimize American astronomy in the eyes of the Europeans.
RACHEL
Her accomplishments don’t end with a comet discovery.
PAUL
That’s right; she and her students were the first astronomers to take daily pictures of sunspots.
RACHEL
She was the first woman elected to the American Association for the Advancement of Science in 1850.
PAUL
She became the first astronomy professor at Vassar College in 1865.
RACHEL
And she was also the director of the college’s observatory.
PAUL
You can learn more about Maria Mitchell on Wikipedia
RACHEL
That’s Idaho Skies for the 1st and 2nd of August.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Welcome to Idaho Skies for August 1st and 2nd. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Stargazers will have noticed that Venus is getting ever closer to the horizon.
RACHEL
This means it’s on it way out of the evening sky.
PAUL
In fact, within six weeks Venus will be lost in the sun’s glare.
RACHEL
So take some time out this evening to look for Venus in the low west.
PAUL
Guess whose birthday it is on the 1st.
RACHEL
It’s the birthday of Maria Mitchell.
PAUL
Did you known that she was the first American woman to become an official astronomer?
RACHEL
One reason why is that she was born a Quaker.
PAUL
The Quaker (faith) religion is famous for viewing men and women as equals.
RACHEL
Which meant she had access to a better education than most women did in 1818.
PAUL
Maria became famous in 1847 when she discovered a comet.
RACHEL
Her comet was too faint for a person to see without a telescope.
PAUL
This made her only the third woman to discover a comet.
RACHEL
And the only American woman to do so.
PAUL
She made measurements of the comet’s position and used that data to calculate its orbit a month later.
RACHEL
Maria’s discovery and work resulted in her being awarded a gold medal by the king of Denmark.
PAUL
One result of this award is that it helped legitimize American astronomy in the eyes of the Europeans.
RACHEL
Her accomplishments don’t end with a comet discovery.
PAUL
That’s right; she and her students were the first astronomers to take daily pictures of sunspots.
RACHEL
She was the first woman elected to the American Association for the Advancement of Science in 1850.
PAUL
She became the first astronomy professor at Vassar College in 1865.
RACHEL
And she was also the director of the college’s observatory.
PAUL
You can learn more about Maria Mitchell on Wikipedia
RACHEL
That’s Idaho Skies for the 1st and 2nd of August.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Idaho Skies Transcript for July 30th and 31st
RACHEL
Welcome to Idaho Skies for July 30th and 31st. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Until 1964, the best pictures of the moon where only available through a telescope.
PAUL
Theoretically, the larger a telescope’s lens or mirror diameter, the smaller the details it can make out.
RACHEL
Unfortunately, atmospheric turbulence blurs the details a telescope can ultimately resolve.
PAUL
And this turbulence limits the resolution of these images of the lunar surface to about one mile.
RACHEL
Recall that three years earlier, President Kennedy announced that we’d land a man on the moon within the decade.
PAUL
Which is difficult if you only know the lunar surface at the scale of one mile.
RACHEL
The way to fix this is to send a spacecraft to the moon and take close up pictures.
PAUL
Which was more easily said than done in the early 1960s.
RACHEL
Because at this time, numerous spacecraft were failing to even reach Earth orbit, let alone the moon.
PAUL
With that in mind, the Jet Propulsion Laboratory designed the Ranger program.
RACHEL
The Ranger series were spacecraft that only needed to get to the moon to be successful.
PAUL
Their mission was simple, just crash into the moon with several a television cameras operating.
RACHEL
Still, the first six attempts failed to either reach Earth orbit, the moon, or even transmit.
PAUL
As a result, people began to question JPL’s ability to even design a successful spacecraft.
RACHEL
But finally, on July 31st, 1964, the seventh Ranger reached the moon and returned close up images of its surface.
PAUL
In fact, it returned over 4,000 images during its 17 minutes moon dive.
RACHEL
And the last one could see details as small as 15 inches across.
PAUL
At the end of its 17 minute mission, Ranger 7 crashed into the lunar surface at a speed of 5,800 miles per hour.
RACHEL
So 54 years ago this week, the US accomplished one of its significant space firsts against our race with the Soviet Union.
PAUL
One that helped heal the sting caused the Soviet Union’s launch of Sputnik 1 six and a half years earlier.
RACHEL
That’s Idaho Skies for the 30th and 31st of July.
PAUL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Welcome to Idaho Skies for July 30th and 31st. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Until 1964, the best pictures of the moon where only available through a telescope.
PAUL
Theoretically, the larger a telescope’s lens or mirror diameter, the smaller the details it can make out.
RACHEL
Unfortunately, atmospheric turbulence blurs the details a telescope can ultimately resolve.
PAUL
And this turbulence limits the resolution of these images of the lunar surface to about one mile.
RACHEL
Recall that three years earlier, President Kennedy announced that we’d land a man on the moon within the decade.
PAUL
Which is difficult if you only know the lunar surface at the scale of one mile.
RACHEL
The way to fix this is to send a spacecraft to the moon and take close up pictures.
PAUL
Which was more easily said than done in the early 1960s.
RACHEL
Because at this time, numerous spacecraft were failing to even reach Earth orbit, let alone the moon.
PAUL
With that in mind, the Jet Propulsion Laboratory designed the Ranger program.
RACHEL
The Ranger series were spacecraft that only needed to get to the moon to be successful.
PAUL
Their mission was simple, just crash into the moon with several a television cameras operating.
RACHEL
Still, the first six attempts failed to either reach Earth orbit, the moon, or even transmit.
PAUL
As a result, people began to question JPL’s ability to even design a successful spacecraft.
RACHEL
But finally, on July 31st, 1964, the seventh Ranger reached the moon and returned close up images of its surface.
PAUL
In fact, it returned over 4,000 images during its 17 minutes moon dive.
RACHEL
And the last one could see details as small as 15 inches across.
PAUL
At the end of its 17 minute mission, Ranger 7 crashed into the lunar surface at a speed of 5,800 miles per hour.
RACHEL
So 54 years ago this week, the US accomplished one of its significant space firsts against our race with the Soviet Union.
PAUL
One that helped heal the sting caused the Soviet Union’s launch of Sputnik 1 six and a half years earlier.
RACHEL
That’s Idaho Skies for the 30th and 31st of July.
PAUL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Idaho Skies Transcript for July 27th, 28th, and 29th
RACHEL
Welcome to Idaho Skies for July 27th, 28th, and 29th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon is full on the 27th.
PAUL
Since the full moon is close to Mars, we know that Mars is near opposition.
RACHEL
This means that a straight line drawn from the sun to Earth would extend to the moon...
PAUL
...and pass very close to Mars if extended farther.
RACHEL
During an opposition of Mars, Earth appears very close to the sun.
PAUL
Recall that when the inner planets, Mercury and Venus, cross the face of the sun from our perspective we call it a transit.
RACHEL
Well, for someone on Mars, Earth can also transit the sun.
PAUL
And these Earth transits occur in cycles of four due to the orbital periods of Earth and Mars.
RACHEL
When a transit cycle begins, Mars sees its next Earth transit 26 years later.
PAUL
After that transit, the third transit of a cycle occurs 79 years later.
RACHEL
And finally, the last transit of a cycle occurs 100 years after the third transit.
PAUL
The last Earth transit occurred on May 11th, 1984 when there were no active spacecraft around Mars to observe it.
RACHEL
And it was the third Earth transit of a cycle.
PAUL
So the next one occurs one hundred years later on November 10th, 2084.
RACHEL
And perhaps Mars will have colonists by then.
PAUL
Just wait until both Venus and Earth transit the sun simultaneously!
RACHEL
That occurs in the year 571,471.
PAUL
That’s Idaho Skies for the 27th, 28th, and 29th of July.
RACHEL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Rachel...
PAUL
...and Paul.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for July 27th, 28th, and 29th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon is full on the 27th.
PAUL
Since the full moon is close to Mars, we know that Mars is near opposition.
RACHEL
This means that a straight line drawn from the sun to Earth would extend to the moon...
PAUL
...and pass very close to Mars if extended farther.
RACHEL
During an opposition of Mars, Earth appears very close to the sun.
PAUL
Recall that when the inner planets, Mercury and Venus, cross the face of the sun from our perspective we call it a transit.
RACHEL
Well, for someone on Mars, Earth can also transit the sun.
PAUL
And these Earth transits occur in cycles of four due to the orbital periods of Earth and Mars.
RACHEL
When a transit cycle begins, Mars sees its next Earth transit 26 years later.
PAUL
After that transit, the third transit of a cycle occurs 79 years later.
RACHEL
And finally, the last transit of a cycle occurs 100 years after the third transit.
PAUL
The last Earth transit occurred on May 11th, 1984 when there were no active spacecraft around Mars to observe it.
RACHEL
And it was the third Earth transit of a cycle.
PAUL
So the next one occurs one hundred years later on November 10th, 2084.
RACHEL
And perhaps Mars will have colonists by then.
PAUL
Just wait until both Venus and Earth transit the sun simultaneously!
RACHEL
That occurs in the year 571,471.
PAUL
That’s Idaho Skies for the 27th, 28th, and 29th of July.
RACHEL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Rachel...
PAUL
...and Paul.
RACHEL
Dark skies and bright stars.
Idaho Skies Transcript for July 25th and 26th
PAUL
Welcome to Idaho Skies for July 25th and 26th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Looking for Mars?
RACHEL
Well, it’s that bright orange star below the moon on the night of the 26th.
PAUL
As we mentioned earlier this week, the air pressure, or more accurately, air density on Mars is very low.
RACHEL
With an air density only 1% of the air density on Earth, the Martian winds are very weak.
PAUL
The winds on Mars must blow ten times faster for them to feel like winds on Earth.
RACHEL
So while nice kite-flying winds can be 10 miles per hour on Earth...
PAUL
...they have to blow at 100 miles per hour on Mars.
RACHEL
In Andy Weir’s novel, The Martian, astronaut Mark Watney is nearly killed in a Martian dust storm.
PAUL
But hurricane force winds like that would have to blow around 1,000 miles per hour on Mars to have that effect.
RACHEL
The novel and movie are, however, correct about the problems of accumulation of wind blown dust.
PAUL
Fine Martian dust is not weathered like dust is on Earth.
RACHEL
This means the dust is very sharp and likely to scratch surfaces.
PAUL
Martian dust would be very effectively lodge into mechanisms that move, like gear trains.
RACHEL
The sharp edges of the dust can then do serious damage to these mechanisms.
PAUL
This means Martian astronauts must regularly clean and lubricate the zippers in their spacesuit to keep them from failing.
RACHEL
The dust represents an additional risk to astronauts because they could inhale it.
PAUL
Just like miners on Earth, Martian astronauts might suffer from silicosis by the long term inhalation of Martian dust.
RACHEL
That’s Idaho Skies for the 25th and 26th of July.
PAUL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Welcome to Idaho Skies for July 25th and 26th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Looking for Mars?
RACHEL
Well, it’s that bright orange star below the moon on the night of the 26th.
PAUL
As we mentioned earlier this week, the air pressure, or more accurately, air density on Mars is very low.
RACHEL
With an air density only 1% of the air density on Earth, the Martian winds are very weak.
PAUL
The winds on Mars must blow ten times faster for them to feel like winds on Earth.
RACHEL
So while nice kite-flying winds can be 10 miles per hour on Earth...
PAUL
...they have to blow at 100 miles per hour on Mars.
RACHEL
In Andy Weir’s novel, The Martian, astronaut Mark Watney is nearly killed in a Martian dust storm.
PAUL
But hurricane force winds like that would have to blow around 1,000 miles per hour on Mars to have that effect.
RACHEL
The novel and movie are, however, correct about the problems of accumulation of wind blown dust.
PAUL
Fine Martian dust is not weathered like dust is on Earth.
RACHEL
This means the dust is very sharp and likely to scratch surfaces.
PAUL
Martian dust would be very effectively lodge into mechanisms that move, like gear trains.
RACHEL
The sharp edges of the dust can then do serious damage to these mechanisms.
PAUL
This means Martian astronauts must regularly clean and lubricate the zippers in their spacesuit to keep them from failing.
RACHEL
The dust represents an additional risk to astronauts because they could inhale it.
PAUL
Just like miners on Earth, Martian astronauts might suffer from silicosis by the long term inhalation of Martian dust.
RACHEL
That’s Idaho Skies for the 25th and 26th of July.
PAUL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
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