Seeds of Life Across the Universe

Narrator (Megan Watzke, CXC): In order for things grow, nature often requires seeds. Think of a farmer who must plant seeds into the ground in the spring or summer in order to have crops to harvest in the fall. This deliberate seeding of fertile soil has produced agriculture as we know it today, and allows us to grow certain crops to bring to market at predictable times of the year.

On a smaller scale, bees are involved with seeding as they moving from flower to flower and gather nectar to feed their hive. By transporting pollen grains from a flower's male parts to female parts of the same species, the bees pollinate and fertilize the flower and enable it to reproduce. In fact, pollination by bees and other animals is crucial to the production of most of the fruits, nuts, and berries on which people and wildlife depend. What's more, about 150 of the crops grown in the United States - including blueberries, apples, oranges, squash, tomatoes and almonds - require the help from pollinating insects and birds.

There is also seeding taking place on a much bigger stage - a cosmic one. When giant stars run out of fuel and collapse, they can explode in what astronomers call supernova explosions. These supernovas spread elements such as oxygen, iron, calcium, and many others into the environment around the exploded star. While these may not sound like "seeds" as we know them on Earth, they are in fact, key ingredients that will be swept up by future generations of stars and planets. It is through this process that the Earth acquired the elements that we require for life here on our planet. On average, a star explodes as a supernova about once every 50 years in our Milky Way galaxy. When it does, it can release more than a billion times the oxygen found in the Earth's oceans and atmosphere combined.

So it is clear how seeding can be important to plants and animals here on Earth, but keep an open mind to how this process has a role throughout the Universe. The growth of new structures - no matter where they are found - often depends on the introduction of new material into an environment. And this seeding can occur here, there, and everywhere in nature, through many different agents and on every scale imaginable.

Return to Podcasts

HD 189733: NASA's Chandra Sees Eclipsing Planet in X-rays for First Time

Narrator (April Hobart, CXC): HD 189733b: An exoplanet in orbit around a star about 63 light years from Earth. It has been nearly two decades since the first exoplanets – that is, planets around stars other than our Sun – were discovered. Now for the first time, X-ray observations have detected an exoplanet passing in front of its parent star. The observations, made by NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton Observatory, took advantage of the alignment of a planet and its parent star in HD 189733. This alignment enabled the observatories to observe a dip in X-ray intensity as the planet moved in front of, or transited, the star. This technique is the one used so successfully at optical wavelengths by NASA's Kepler telescope. In earlier studies using optical light, astronomers discovered that the main star in the HD 189733 system had what is known as a "hot Jupiter" around it. This means the planet is about the size of Jupiter, but in very close orbit around its star. The planet – that has been named HD 189733b -- is over 30 times closer to its star than Earth is to the Sun, and goes around the star once every 2.2 days. The new X-ray data suggest that this planet has a larger atmosphere than previously thought. This, in turn, may imply that radiation from the parent star is evaporating the atmosphere of HD 189733b more quickly than expected. The results on HD 189733 demonstrate how we need information from many different telescopes that detect different types of light to get a fuller picture of these mysterious worlds that we are now able to explore.