Transcript for May 19 to 25

PAUL
Welcome to Idaho Skies for the fourth week of May. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
May 20th is the 25th anniversary of the launch of Pioneer Venus 1. After entering orbit, it spent a decade exploring Venus.

RACHEL
It used a simple radar system to map the planet’s surface.

PAUL
Thick opaque clouds cover Venus and radar is the only way to penetrate this layer of sulfuric acid clouds.

RACHEL
Spica is the bright star to left of moon on the evening of the 21st.

PAUL
The separation between them is 3½ degrees; therefore, they will both comfortably fit within your binoculars at the same time.

RACHEL
Even though they appear close together, their distance apart in three dimensions is immense.

PAUL
That’s right. It takes light only 1½ seconds to travel the distance between us and the moon. Spica on the other hand requires a trip of 263 years.

RACHEL
On the 22nd, the moon is your guide to Saturn.

PAUL
The ringed planet will appear to the upper left of the moon late that evening.

RACHEL
While the moon is a spectacular binocular and telescope object, Saturn requires a telescope.

PAUL
However, even a small telescope at low power is enough to show the planet’s ring system and largest satellite, Titan.

RACHEL
Another planetary event is taking place on the other side of the sky.

PAUL
For the next week, Jupiter, Venus, and Mercury are approaching one another.

RACHEL
They’re close to the west-northwestern horizon. So you’ll need to look around 9:30 PM. If you find them, all three will fit within your binoculars at the same time.

 PAUL
And their configuration will get more tightly grouped over the next four days.

RACHEL
Five years ago on the 25th, the Phoenix lander arrived on Mars.

PAUL
The mission of the Phoenix lander was to explore the role and history of water on the Martian surface.

RACHEL
Its landing site was located in the arctic region of Mars where scientists believed water would accumulate as ice.

PAUL
A camera on the lander showed that its landing engines blew loose dust off of a layer of ice buried just beneath the Martian soil.

RACHEL
What appears to be water drops, were seen clinging to the landing legs before they eventually sublimated away.

PAUL
No one expected to see drops of liquid water on Mars, as its atmospheric pressure is far too low for water to exist in the liquid phase.

RACHEL
One reason that water might be able to exist for a short time as a liquid is that the Martian artic soil contains a perchlorate salt.

PAUL
Perchlorate can act as antifreeze and that makes liquid water a little more stable in extreme conditions.

RACHEL
Signs gathered by this lander and other spacecraft now indicate that the planet once had a wetter climate.

PAUL
That’s Idaho Skies for the fourth week of May. Join us next week to hear about two great opportunities to observe four planets.

RACHEL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com For Idaho Skies this is Rachel…

PAUL
and Paul.

RACHEL
Dark skies and bright stars.