A webcast for the International Year of Astronomy 2009 called "Around the World in 80 Telescopes" can be accessed at http://eso.org/public/events/special-evt/100ha.html. The 80 telescopes are situated all over, including Antarctica and space. Pick two of the telescopes and watch the videos, Do you think these videos are effective for public outreach for the observatory in question or for astronomy in general? For each telescope you choose, answer the following questions: Does the telescope observe in the Northern Hemisphere or the Southern Hemisphere? What wavelengths does the telescope observe? What are some of the key science projects at the telescope?

Astronomical observation is the process of using telescopes and other instruments to capture and record data about celestial objects and phenomena. There are many different types of telescopes, each designed to observe specific wavelengths of light or other electromagnetic signals. These telescopes can be positioned on Earth or in space, depending on the observation needs and the nature of the objects being studied.

Telescopes on Earth need to be strategically placed to avoid light pollution and atmospheric interference. This is why observatories are often located in remote areas, like mountainous regions or deserts.

Telescopes in space, on the other hand, are unaffected by the Earth's atmosphere, which allows for clearer and more detailed observations of the universe.

Astronomical observations help scientists understand the composition, movement, and behavior of celestial objects such as stars, planets, galaxies, and nebulae.

Different telescopes are designed to observe different wavelengths of light. Each wavelength provides unique information about the celestial objects being observed.

For example:

• Visible light telescopes capture the same light that our eyes can see.
• Radio telescopes observe radio waves, which can penetrate dust clouds and reveal information about the structure and dynamics of galaxies.
• Infrared telescopes detect heat emissions, which are useful for studying cooler objects like planets, asteroids, and the dust around stars.
• Ultraviolet telescopes look at high-energy processes and hot objects, like young stars and supernova remnants.
• X-ray telescopes are important for studying extremely hot and energetic phenomena such as black holes and neutron stars.
• Gamma-ray telescopes follow the highest-energy wavelengths and can help us understand events like gamma-ray bursts.

By combining observations across multiple wavelengths, astronomers can gain a deeper and more comprehensive understanding of the universe.

Public outreach in science is crucial for educating and engaging the general population about scientific discoveries and concepts. It involves a variety of activities and platforms, such as:

• Webcasts and online videos that make scientific research accessible to a global audience.
• Public lectures and workshops held at observatories or science museums.
• Interactive exhibits and planetarium shows that provide hands-on learning experiences.
• Social media campaigns to disseminate scientific information in a relatable manner.

Effective public outreach helps to inspire the next generation of scientists, fosters public support for scientific research, and enhances general scientific literacy. It can also demystify complex scientific topics, making them approachable and exciting for a broader audience.

Key science projects refer to the main research initiatives and studies conducted using telescopes and other observational instruments. These projects often focus on important questions about the universe, such as:

• Understanding the formation and evolution of galaxies.
• Studying the life cycles of stars, from their birth in stellar nurseries to their deaths in supernova explosions.
• Searching for exoplanets and assessing their potential for habitability.
• Observing black holes and the effects of their immense gravitational fields.
• Investigating dark matter and dark energy, which comprise a large portion of the universe's mass and energy yet remain poorly understood.

Each key science project contributes valuable data that enhances our knowledge of the cosmos, leading to new insights and discoveries. These projects are often collaborative efforts involving multiple observatories and international research teams.

Observatories around the world are strategically located in both the Northern and Southern Hemispheres to provide complementary views of the sky. This is essential because some celestial objects and phenomena are best observed from specific latitudes:

• Northern Hemisphere telescopes are positioned to observe the northern sky, including objects like the North Star (Polaris) and the Andromeda Galaxy.
• Southern Hemisphere telescopes can capture views of the southern sky, featuring the Milky Way's center, the Magellanic Clouds, and Eta Carinae.

By having observatories in both hemispheres, astronomers can conduct more comprehensive sky surveys and studies. This global coverage ensures that no part of the sky is left unexplored, leading to a more complete understanding of the universe.