Category Archives: astronomy

Happy Anniversary, HUBBLE!

Hubble Space Telescope launch.
Hubble Space Telescope on its way to orbit aboard space shuttle Discovery. Courtesy NASA.

It’s hard to believe that it’s been 30 years since the Hubble Space Telescope was launched into orbit on April 24, 1990. On the whole, they’ve been very good and productive years, despite the mission’s rocky beginning. Without it, our knowledge of the universe would be less advanced than it is today.

Following Hubble from the Beginning

HST has played a big role in my life, and I’ve followed it avidly through the decades. For several years, I was a student at the University of Colorado, working toward a graduate degree. During part of that time, I was also a member of the HST/Goddard High Resolution Spectrograph team led by friend and co-author John C. Brandt. I joined the group about a month before launch, although I’d been working for him for a couple of years on comet images for a big atlas we were producing. Working with HST data and proposals (as I hoped to do) was a big incentive to join his team. (I go into more detail about that job and my first impressions of HST in this entry from 2015. And, you can search out many other stories I’ve done here by typing “Hubble Space Telescope” in the search box.)

The day of launch was pretty exciting. I remember watching from home (since it happened in early morning). Then, we waited for the first-light images. Our team leader shared some concerns they were having with focusing the images. Eventually, through persistent questioning and investigation by such folks as Dr. Sandy Faber and others, the bad news came out: the telescope’s mirror had a problem called “spherical aberration”. It meant the main mirror was ground precisely wrong and that images would look incredibly fuzzy and out of focus.

galaxy M100 before and after Hubble Space Telescope was repaired
This comparison image of the core of M100 shows Hubble Space Telescope views before and after it was refurbished to correct for spherical aberration. Corrective optics inside the Wide Field and Planetary Camera 2 (WFPC-2) were able to sharpen the view. Courtesy NASA/ESA/STScI.

The news was devastating. We talked about what effect the spherical aberration would have on our instrument. It was not good. But, over time, as we all know, the HST teams were able to come up with ways to treat the images and data to pull out as much data as they could. And, eventually, the telescope started returning the “pretty pictures” that we all craved. It made my secret ambition to collect good images and information a bit easier.

Telling a Tale of Hubble Science

I began working on an article that then became a possible thesis topic, and eventually a book. Hubble Vision was published in 1995, just a few short years after launch and the first servicing mission. It was the first book to focus almost exclusively on HST science and it was written to share Hubble’s scientific achievements with the general public. My goal was to tell the tale of the telescope’s history, and then focus on the science story, not gossip and politics. I invited Jack to join me as the second author, and between us, we told a compelling tale of discovery. I’m still very proud of it.

Other writers made more money selling negative stories, but I felt good talking about the science. No matter how hard it was to get. I still write about HST science today, and it’s still cranking out good science. My most current book, The Discovery of the Universe, examines it as part of a family of space- and ground-based observatories that together continue our exploration of the cosmos.

Hubble’s Views of the Universe

I left the GHRS team when I graduated, and have since gone on to write about Hubble’s imagery and science many times in articles, books, and in this blog. Nothing the telescope sees fails to amaze me. Even the blobbiest-looking elliptical galaxy that HST shows us has a compelling story to tell. Throughout the 30 years of its mission, HST has studied the closest planets and the most distant objects in the observable universe. It taught us to see beyond our preconceptions of the cosmos, to learn that there are still new things to discover “out there.

Hubble’s First Deep Look

The first image that really took my breath away in Hubble’s early days was the very first Hubble Deep Field. This “core sample” of a tiny spot in the sky near the constellation Ursa Major, blew people away. I remember standing in front of it at a meeting of the American Astronomical Society in 1996, marveling at the detail.

Essentially, astronomers used Hubble to peer across billions of light-years, back to a time when the universe was very young. The Deep Field showed that galaxies exist as far as we could see. Some of them looked like shreds of galaxies, others looked fully formed.

Hubble Space Telescope first Deep Field image.
The first deep field image taken by Hubble Space Telescope. It revealed distant galaxies in the early universe. Courtesy NASA/ESA/STScI

The success of that image led to other deep field observations, in other directions of the universe. As far as we can tell, it’s galaxies (and their precursors) all the way out. And, today, thanks to HST, we have a much better idea of conditions in the early universe, back when the first stars and galaxies began to form.

That, to me, is one of the many incredibly enduring legacies that Hubble Space Telescope and the astronomers who’ve used it have created. I was pleased to be able to put it in the second edition of Hubble Vision. I also used later deep field images taken by the telescope in a very popular fulldome show about HST, now in its own second “edition”, called Hubble Vision 2.

Hail Hubble!

I encourage everybody to check out the many gorgeous images and news stories about the Hubble Space Telescope amassed by the folks at the Space Telescope Science Institute. They maintain a fantastic news site and have created a celebration page featuring links to great images, videos, and articles.

Help celebrate 30 years of remarkable achievements. Like everyone else who has ever met an obstacle and succeeded despite it, the Hubble Space Telescope and its science teams and astronomer-users have done the same. In the process, they have brought us new looks at the ever-changing universe.

ACtion at the Heart of a Black hole

Remember the big black hole announcement last year about this time? A group called the “Event Horizon Consortium” (EHC) announced the first-ever “picture” of a black hole at the heart of the distant galaxy M87. It was made by linking up the highest-powered radio telescopes around the world. They focused on the galaxy and provided incredibly high-resolution information about the region at the event horizon.

Now, astronomers are talking about black hole activity at the heart of another object, called 3C 279. It’s a powerful quasar at the core of a distant galaxy, some five billion light-years away. The radio signals and light that we see from it today show it as it looked before our Sun and planets had even begun to form.

An artist’s concept of what quasar 3C 279 and its galaxy might look like. Credit: ESO/M. Kornmesser.

Quasars are galaxies in the distant (and younger) universe with energetic activities at their hearts. In visible light, they are incredibly bright, but they also radiate in many other forms of light. What is happening inside these galaxies? Astronomers long searched for ways to explain these incredibly bright objects.

I remember one researcher musing about the engines powering quasars. They said that if a black hole wasn’t a good explanation for quasars, then it had to be something MUCH weirder. Imagine what could be stranger? Black holes certainly provide that “engine”. It’s powerful enough to cause quasars to emit across the electromagnetic spectrum. So, the comment seemed prophetic.

A Twisted Pair of Jets

The quasar 3C 279 has a pair of twin jets. In the area where the jet originates, superheated gases swirl around in a disk surrounding the black hole’s event horizon. Incredibly strong magnetic fields also exist there. They channel some of the hot material to create energetic outflows. Based on EHT observations, the jets send material out at something like 99.5% of the speed of light. That indicates a very active and powerful “push” caused as matter funnels into the black hole’s gravity well.

The collection of radio telescopes used by the EHT zeroed in on the area where the jet activity originates. Astronomers used observations of this quasar as a “pathfinder” and calibration object in 2017.

The data show the base of the jet as it twists over time. Could it be that accretion disk’s rotation and shredding of infalling material are affecting the shape of the jet? Are the incredibly strong magnetic fields playing a role? It’s all part of figuring out how black holes accrete material around them. In addition, it gives more insight into how strong magnetic fields cause the jets to form in the first place.

More observations will help fill in the story of this jet at 3C 279, once EHT is up and running again. At the moment, the world-wide array is shut down due to the CoVID-19 pandemic. EHT scientists are busy analyzing data from the most recent observations.

Here’s an animated look at the activity in 3C 279 over the course of a week, taken in April 2017.