Startalk Radio – Things You Thought You Knew – Where the Sun Don’t Shine

Intro

In this episode of Startalk Radio, the hosts explore various misconceptions and fascinating facts about the sun, the moon, and space travel. From the concept of “high noon” to the existence of water molecules on the moon, they delve into the science behind these phenomena and shed light on the mysteries of our celestial neighbors.

Main Takeaways

The Sun’s Position and Earth’s Tilt

• At 12 noon, the sun is never directly overhead in the continental United States.
• People think the sun is directly overhead because of the word “high” in “high noon.”
• The concept of “high noon” comes from a Western shootout.
• The sun is occasionally directly overhead between 23.5 degrees north and south latitude due to the tilt of Earth’s axis.

The Moon and Sunlight

• Looking directly at the sun is dangerous and should be avoided.
• The tropics are the areas on Earth where the sun is directly overhead on certain days of the year.
• The highest the sun gets in any day of the year is lower as you approach the poles.
• At the Arctic Circle, there is a day where the sun never sets and stays that way throughout the summer.
• At the South Pole of the moon, the height of the sun above the horizon doesn’t get very high, so the base of some craters at the sun never sees sunlight.

Water on the Moon and Space Travel

• The height of the sun above the horizon changes seasonally, with the highest point being during the summer solstice and the lowest point being during the winter solstice.
• On the moon, there is no air or sky getting illuminated by sunlight, which is why we do not see a blue sky.
• Stars are not visible in photos taken on the moon because the terrain is too bright for the camera to register dim light.
• Water molecules on the moon’s surface can stay frozen in cold traps for billions of years and will be explored in NASA’s Artemis 3 mission.
• NASA’s Artemis 3 mission will explore frozen water molecules on the moon’s surface that can stay frozen in cold traps for billions of years.

Gravity and Space Exploration

• In situ resource utilization (ISRU) is a NASA concept that aims to use resources found on the moon, such as water, instead of bringing them from Earth.
• The low position of the sun at the poles makes it an interesting and challenging place to explore.
• Water on the moon could be mined through the lunar material and used for various purposes, including ice skating.
• Weightlessness in space is not due to the absence of gravity, but rather the absence of a net gravitational force acting on objects.
• When in orbit around Earth, objects are falling towards Earth but also moving forward at a high enough speed to keep missing it.

Summary

The Sun’s Position and Earth’s Tilt

Contrary to popular belief, the sun is never directly overhead at 12 noon in the continental United States. The concept of “high noon” originated from Western shootouts and does not reflect the sun’s actual position. However, between 23.5 degrees north and south latitude, the sun can be directly overhead due to the tilt of Earth’s axis.

The Moon and Sunlight

Looking directly at the sun is dangerous and should always be avoided. The tropics are the regions on Earth where the sun is directly overhead on specific days of the year. As you move closer to the poles, the highest point the sun reaches in a day decreases. For example, at the Arctic Circle, there is a day where the sun never sets during the summer. On the moon, the height of the sun above the horizon is limited, resulting in some craters never receiving sunlight.

Water on the Moon and Space Travel

The height of the sun above the horizon changes seasonally, with the highest point during the summer solstice and the lowest point during the winter solstice. On the moon, there is no atmosphere or sky to be illuminated by sunlight, explaining the absence of a blue sky. Additionally, stars are not visible in moon photographs due to the bright lunar terrain. NASA’s Artemis 3 mission aims to explore frozen water molecules on the moon’s surface, which can remain frozen in cold traps for billions of years.

Gravity and Space Exploration

NASA’s concept of in situ resource utilization (ISRU) focuses on using resources found on the moon, such as water, instead of relying on supplies from Earth. The low position of the sun at the poles makes them intriguing yet challenging places to explore. Water on the moon could potentially be mined and utilized for various purposes, including ice skating. Weightlessness in space is not due to the absence of gravity, but rather the absence of a net gravitational force. Objects in orbit around Earth are constantly falling towards it but also moving forward at a high speed to maintain their trajectory.

Conclusion

Exploring the sun, moon, and space travel reveals fascinating insights about our celestial neighbors. From debunking misconceptions about the sun’s position to uncovering the potential of water on the moon, these discoveries expand our understanding of the universe. As we continue to explore and utilize resources in space, we gain valuable knowledge that shapes the future of space exploration.