What is the nature of the Universe in which we live? This is probably one of the most profound questions human beings can ask. And for the majority of human history, that question could only find answers in philosophy or religion; we lacked the tools to look deeply into the cosmos, to see what was going on. Enter the Big Bang, a theory of the Universe where everything began from a single point, and has been rapidly expanding ever since. In his latest book, Big Bang, Simon Singh explores the history and series of discoveries that have led astronomers and theorists to our current understanding of our place in an expanding Universe.

NASA's Deep Impact mission completed its primary goal July 4th, when its impactor spacecraft smashed into Comet Tempel 1. NASA scientists are eagerly reviewing the impact data captured by the flyby spacecraft to learn what size crater was excavated, and the kind of material ejected into space. The 373 kg (820 lb) copper impactor crossed paths with Tempel 1 right on schedule, at 0552 UTC (1:52 am EDT). More than 60 observatories on Earth and in space were on hand to watch the collision and help gather data. As expected, Comet Tempel 1 was entirely unfazed by the impact, and hasn't changed its orbit in any detectable way.

It always happens. You go to buy something. You've got a list of all the necessary parameters, you've set a budget and you've short listed the merchants. Then you end up back at home with a really neat gizmo that looks sharp, costs way too much and doesn't really do what you need. Emotions are to blame as they take over your reasoning and lead you on a completely unexpected journey. Simon Mitton shows similar a similar rational for Fred Hoyle in his biography Conflict in the Cosmos, Fred Hoyle's Life in Science. In it is a very storied career that sometimes proceeds in expected directions while other times progresses along wholly inexplicable paths.

Astronomers have found an extrasolar planet that contains the largest core ever seen in a planet. This planet orbits the Sun-like star HD 149026, is roughly the size of Saturn, and takes only 2.87 days to complete its year. The planet was first discovered by the effect of its gravity around its parent star. Astronomers were then fortunate to detect how much it dims the light from the star as it passes in front. From this information, they were able to measure the planet's size, and calculate the size of its core. This discovery adds evidence to the "core accretion" theory of planetary formation, where planets start as balls of rock and ice, and collect a gas envelope around themselves.

The powerful Hubble Space Telescope was on hand to watch the collision between Deep Impact and Comet Tempel 1. Even though Hubble is one of the most sensitive telescopes available, the shroud of dust and gas surrounding Tempel 1 obscures a view of the comet's nucleus. Hubble was able to see the flash from the impact, making the comet 4 times as bright, and then an expanding fan of debris moving away from the comet.

Greetings, fellow SkyWatchers! The big news is Deep Impact, and while we're waiting we'll view the "Cat's Eye". With New Moon this week, there will be plenty of opportunities to check out the cometary action as well as some very unusual star clusters. As the week ends, be sure to enjoy the picturesque twilight as the Moon returns to join the planetary show. It's time to open your eyes to the skies, because...

Here's what's up!

NASA's Deep Impact spacecraft released its impactor "probe" Sunday morning, and changed its trajectory to pass a comfortable distance from Comet Tempel 1. When it was released, the impactor was 880,000 km (547,000 miles) away from Tempel 1. After releasing the impactor, Deep Impact began firing its engine for 14 minutes, which slowed down, and kept it out of the path of the onrushing comet. If all goes well, the impactor will strike Tempel 1 on Monday, July 4 at 0652 UTC (1:52 am EDT).

This year NASA's Institute for Advanced Concepts (NIAC) has selected a dozen new-fangled ideas that could lead to revolutionary changes in the way we explore the near and far solar system. Among these advanced concepts was a proposal headed up by Dr. Gerald A. Smith, of Positronics Research LLC, Santa Fe, N.M. whose "Positron-propelled and Powered Space Transport Vehicle for Planetary Missions" could lead to the kind of high-efficiency propulsion systems needed to get there and back without having to cart vast quantities of chemically-based fuel and oxidizer along for the ride.

University of Chicago researcher Nicolas Dauphas has developed a new method to calculate the age of the Milky Way by measuring two long-lived radioactive elements in meteorites. By calculating the amount of uranium-238 and thorium-232, Dauphas determined that the Milky Way is approximately 14.5 billion years old, give or take 2 billion. This is a close match for the age of the Universe, calculated to be 13.7 billion years by NASA's WMAP spacecraft. This means that it probably didn't take much time after the Big Bang for large structures, such as the Milky Way, to form.

The European Space Agency's Rosetta spacecraft has captured its first photograph of Comet 9P/Tempel 1, Deep Impact's target. Rosetta is quite distant, so Tempel 1 is at the very limits of its detection abilities. The spacecraft will help analyze the gas, ice and debris that spew off of Comet Tempel 1 when Deep Impact smashes into it on July 4. This is just a job on the side, though, as Rosetta has a date with its own comet, 67P/Churyumov-Gerasimenko, in 10 years from now.

How many times have I been to space? Well, I lost count at, oh, none. So I, and nearly every other human being on Earth can't compare with Story Musgrave, a legendary NASA astronaut who flew on the space shuttle six times, including leading the team that fixed the Hubble Space Telescope's vision in 1993. He's the subject of a recent biography called Story: the Way of Water, and has a new CD called Cosmic Fireflies, which sets his space inspired poetry to music. Story speaks to me from his home in Florida.

Our Sun is in the middle age of life, and that's a good thing for us here on Earth. But in a few billion years, when the Sun runs out of hydrogen to fuel its massive fusion furnace, it will balloon into a massive red giant, engulfing the inner planets, including the Earth, before it shrinks again into a white dwarf. Is that the end of our solar system? Maybe not. Although they might get a little (okay... a lot) scorched, the outer planets might actually survive the experience in one piece. German researchers have found the first planet orbiting a white dwarf star, so there appears there's a future for planets when their star becomes a red giant.

A key instrument for the search of life on Mars has discovered it in one of the most inhospitable places on Earth. The instrument, called the Mars Organic Analyzer, will be installed into the European Space Agency's ExoMars mission due for launch in 2011. It was able to see evidence of amino acids, the building blocks of proteins, in soil at Chile's Atacama desert. The next step will be to build an instrument that can fit in the allowed space of the ExoMars spacecraft.

NASA's Deep Impact spotted an outburst of ice and gas from the surface of Comet Tempel 1, which has been turned into a short animation of several frames. This is the second outburst astronomers have seen from the comet this month, and gives astronomers a great opportunity to fine tune instruments in space and here on Earth to get the most science out of the July 4 "encounter".

Planetary scientists have speculated that there could be lakes of liquid hydrocarbons on the surface of Titan, Saturn's largest moon, and now they've found an intriguing dark patch on the moon's surface that could be an open body of liquid. This photograph is a view of Titan's southern pole, a region that often has storm clouds, so it's an ideal candidate for an open lake. If it isn't a lake, the region could be a large hole that filled with solid, dark hydrocarbon "snow". The red cross in this image marks Titan's south pole.

NASA's Cassini spacecraft took this photograph of Janus, one of Saturn's many moons. The 181 km (113 mile) moon is covered with craters and patches of dark material exposed by numerous impacts. Astronomers think that Janus may be a porous object, largely composed of water ice. This image was taken when Cassini was approximately 357,000 km (222,000 miles) away from Janus.