The Great Nebula in Orion is a intriguing place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. But this image, an illusory-color composite of four colors of infrared light taken with the Earth orbiting WISE observatory, shows the Orion Nebula to be a bustling neighborhood or recently formed stars, hot gas and dark dust. The power behind much of the Orion Nebula (M42) is the stars of the Trapezium star cluster, seen near the center of the above wide field image. The eerie green glow surrounding the bright stars pictured here is their own starlight reflected by intricate dust filaments that cover much of the region. The current Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next 100,000 years. Credit: NASA,JPL-Caltech,UCLA

Michelle Thaller is the Assistant Director of Science at Goddard Space Flight Center at NASA. She contributed this article toSpace.com's Expert Voices: Op-Ed & Insights.

A lot of people ask me if being an astronomer changes the wayIlook at life. To some degree, I guess there's no way it couldn't. There's a lot you have to let go of things that seem so obvious and straightforward in people's everyday lives take on a scale and complexity that the human brain can't process. So you give up trying. I have no idea what it really feels like to travel through a distance like a light-year, a little more than a trillion miles. I can't easily visualize what 1,000 of something is, let alone a billion.

My mind doesn't grasp the scale of the universe any better than anyone else's, yet this is the environment that I go to work in, talk to my friends at cocktail parties about and muse about with my husband before we turn off the lights. Andrew (said husband) works on the James Webb Space Telescope (JWST), which, when launched, will have the power to peer into the universe more than 13 billion light-years away. Effectively, it will look back to the time when the first stars began to shine. So he knows about this stuff. We often hold hands and buffer ourselves against all this scale. We even have an expression for it: "You still have to feed the cat."

Whenever we're listening to a particle-physicist friend of ours describe multiple rolled-up dimensions or reading the latest paper that asserts that space and time don't really exist and maybe we're all just asingle quantum-entangled particle, we look at each other with some wistfulness and repeat our cat mantra.

All those discoveries can be overwhelming, and sometimes it behooves us to remember that, in fact, there are some fixed points of certainly in it all. My cats would agree with that, or at least there would be hell to pay if we forgot to feed them, lost in the rapture of the cosmos.

In my podcast on the Transistor series, "The Ultimate Wayback Machine," I speak to two exceptionally brilliant women, Nancy Grace Roman, former chief of astrophysics, solar physics and relativity at NASAs Office of Space Science and Jane Rigby Deputy Project Scientist for Operations of the James Webb Space Telescope, about what time really means when you have to let go of the idea that there is a real past, present and future.

For example, consider what you see when you look up at a single constellation. Orion has always been my favorite, and I do a little dance every year when I see it for the first time in the autumn sky seriously. I've also published papers on some of the stars in Orion's belt, which are actually ginormous monsters: closely bonded binary stars that race around each other, orbiting in just a few days. The stars you see in that constellation are not all at the same distance from Earth, so the light has taken different amounts of time to reach your eye. You're not seeing a single point in time, but a span of several hundred years that somehow all arrives at your eye together, all at once. That gives me some pause, every time I look up at what now seems like an old friend in the sky.

But letting go of human perspective doesn't stop there. Not only does the universe leave the human sense of scale and time woefully in the dust, but people's literal senses what they can see, hear, smell and touch are also an incomplete picture of what is happening. Take sight: Human eyes are sensitive to only a tiny range of light energies. All around you, information about an invisible world is pouring into your eyes, but nothing in your retina reacts with it; no signal neurons are fired to send information to your brain that something is right in front of you. []

Again, take Orion: The space between the stars in this constellation are filled with gas and dust from a vast stellar nursery that is churning out hundreds of new stars at this moment. Near the top of the familiar figure of Orion is the star Meissa (or Lambda Orionis), which is ringed by an expanding shell of gas 130 light-years across, the remnant of a spectacular stellar tantrum. If your eyes could detect infrared light, light that is just a bit too low in energy to react with human retinas, you would see Orion filled with huge, glowing rings and clouds stretching between the stars.

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The 'Cat Mantra': How Astronomers Handle an Ungraspable Universe (Podcast)