Collecting and Mapping Planetary Data

Direct measurements (in situ)

• Collecting data directly at the site of scientific interest

• Ground stations on Earth

• Landers and atmospheric probes for other planets

Direct measurements (in situ)

Ground Weather Station

Mars Exploration

Rover

Mars Phoenix Lander

Remote Sensing• Gathering information about an object without

coming into direct contact with the object.

Telescopes gather light from distant planets, stars, and galaxies.

Satellites orbiting the Earth collect information about the weather.

Most scientific remote sensing,particularly from satellites, involves

light…

but not necessarily light as you might typically imagine!

The Electromagnetic Spectrum

• All light has a particular energy, and each energy reveals different information

• Humans are only able to see a small range of these energies, known as the visible spectrum

• Other types of light include gamma rays, x-rays, ultraviolet light, infrared light, and radio waves.

Let’s take a look at some of these different types of light, and

what we can do with them.

Radio Wave Light• Radio waves are the

lowest energy in the spectrum.

• Radio waves are used to transmit radio and television signals and to map the surfaces of planets that are obscured at other wavelengths.

Saturn

Infrared Light• One use of infrared

light is thermal imaging.

• Objects at common Earth temperatures release infrared light that can be used to determine surface temperature.Saturn

Visible Light

• Visible light is the portion of the electromagnetic spectrum that we can detect with our eyes.

• Red light is lower energy than violet light.

• All the colors of the rainbow combine to make white light.

Saturn

Ultraviolet Light

• Some insects, including bees, can see UV light.

• Astronomers can use ultraviolet light to study energetic objects in the universe.

Saturn

X-Ray Light• X-rays pass through

some objects better than others.

• Medical X-ray images are actually shadows of objects that x-rays could not pass through.

Saturn

Gamma Ray Light• The highest energy in the

electromagnetic spectrum.• Generated by some

radioactive elements and events resulting from nuclear processes.

• Gamma ray light can be used to map elemental composition of planets.

GRS and THEMIS Remotely Sense Mars

How are gamma rays and neutrons produced by cosmic rays?

Gamma Ray Animation

Play Gamma Ray Animation

Potassium Map of Mars

Potassium Map of United States

Why Do We Care?

• Although each of these types of light are found in the electromagnetic spectrum, they are created in different ways and give us different types of information.

Remote Sensing• Orbiting satellites can

detect light of various energies.

• Shown here are a visible image of Lake Tahoe and a surface temperature map made with infrared data

• We can represent remote sensing data using false color images.

Mapping Activity

Surface Air Temperature Data

Calculated Soil Moisture DataJuly (1971-2000)

Martian Map of WaterTest for Understanding

Describe the distribution of water on Mars