Hot Topics | International Year of Astronomy 2009

Hot Topics: Explore Your Universe!

The universe is yours to discover! Join us each month of 2009 in exploring a new chapter in humankind’s ongoing quest to observe, explore, and understand the universe. Discover how telescopes and space probes have changed and continue to transform our view of the universe, and check out the questions that remain to be answered. Our "Hot Topics" section will connect you to exciting NASA discoveries, plus activities and resources that you can use on your personal journey through the universe. These include IYA Discovery Guides from NASA’s partner, the Night Sky Network, complete with a hands-on activity for each theme plus tips for viewing the celestial objects in our Go Observe! section.

Here are our hot topics for each month of 2009:

January - Telescopes and Space Probes — Today’s Starry Messengers: We celebrate the ongoing contributions of NASA’s telescopes and space probes to the scientific legacy that Galileo initiated 400 years ago with his celestial observations and the publication of Siderius Nuncius - "The Starry Messenger."
February - Our Solar System: Galileo’s observations of the Moon, Jupiter, Venus, and the Sun revolutionized our understanding of the solar system and our place in it. NASA’s explorations of our solar system - and observations of planets around other stars - continue the revolution, sparking the imagination of learners of all ages.
March - Observing at Night... and in the Day: For centuries, observers enjoyed spectacular celestial views afforded by naturally dark skies, but were limited to observing light that we can detect with our eyes. Today’s observers face challenges associated with excess artificial lighting, while benefiting from technology that allows us to detect the full range of the electromagnetic spectrum and to carry out observations day and night.
April - Galaxies and the Distant Universe: In turning his telescope to the hazy band of light that marks our Milky Way galaxy, Galileo discovered countless faint stars. Four centuries later, NASA’s telescopes allow us to peer through the dust that obscures the center of the Milky Way, to study galaxies beyond our own in exquisite detail, and to explore the most distant reaches of the observable universe.
May - Our Sun: Observations of sunspots made by Galileo and his contemporaries challenged prevailing ideas that stated that the Heavens were perfect and unchanging. Today, we use modern technology to collect all forms of light from our nearest star, and to determine how solar weather affects our home planet.
June - Clusters of Stars: Galileo viewed the Pleiades star cluster through his telescope, discovering stars too faint to be seen with the unaided eye. Today, NASA’s telescopes help us to decipher the ages and distances of clusters of stars – both young and old – throughout our galaxy and beyond.
July - Black Holes: The gravitational fields of black holes are so strong that nothing, not even light, can escape. While the idea that such an object could exist arose in the 18th century, finding evidence required modern technology. NASA’s space-based telescopes identify and study these enigmatic objects by the effects that they have on their surroundings.
August - Rocks and Ice in the Solar System: For hundreds of years, much of our knowledge about the smaller rocks and icy bodies in our solar system came from meteors and comets passing by Earth. Modern telescopes and space missions have allowed us to identify vast numbers of small objects in our solar system, and to study them as never before. Scientists reclassified Pluto as a dwarf planet in August 2006 as a result.
September - Planets and Moons: Galileo observed craters and mountains on the Moon, four of Jupiter’s moons, the phases of Venus, and Saturn’s rings. NASA’s missions send us spectacular images of planets and moons throughout our solar system, showing us evidence for past water on Mars, volcanic activity on Jupiter’s moon Io, and never-seen-before views of the planet Mercury.
October - What is the Fate of the Universe?: We have contemplated the origins and fate of the universe for centuries. Scientists using modern telescopes have measured the afterglow of the Big Bang, determined the age of the universe, and discovered that an unexplained force we call "dark energy" is changing our universe, causing it to expand at an increasing rate. What is dark energy, and how will it influence the fate of the universe?
November - The Lives of Stars: A glimpse at the night sky on a clear dark night told the earliest observers that all stars are not the same. Modern telescopes allow us to explore the life cycles of stars in a profound way. We have observed newborn stars emerging from pillars of gas and dust, and captured stunning images of structures formed by dying stars.
December - Discovering New Worlds: The work of Galileo, Johannes Kepler, and other scientists of the time had a dramatic impact on science and culture. Today’s telescopes, space missions, and research place us on the brink of another revolution, as they reveal that the worlds of our solar system differ dramatically from Earth, that hundreds of planets orbit other stars, and that life can exist in a wide range of environments.