Alex’s Space

The annual Perseid meteor shower (arguably the best meteor shower of the year) will peak on the night of August 11/12, but the nights of August 9/10, 10/11, 12/13, and 13/14 should reveal some Perseids as well. The first-quarter Moon will set around midnight, so skies will be dark (if you’re away from city lights).

In general, view Perseids after 11 pm local time — or better, after 12 am (indeed, the pre-dawn hours should actually yield the largest hourly rate). Before about 11 pm, few Perseids are visible — though they should be longer streaks than average, skimming through Earth’s atmosphere because the “radiant” Perseus from which they appear to come will be closer to the horizon. Also, you don’t have to account for your specific *time zone* — the times I list above are fine *regardless* of where you are (though the northern hemisphere is more favorable than the southern hemisphere, for this particular shower).

The meteor shower occurs because Earth flies through debris from Comet Swift-Tuttle (whose orbital period in a long ellipse is about 130 years), and the little bits of ice and mostly rock (typically the size of a grain of sand or a small pebble) will burn up as they zip through Earth’s upper atmosphere (altitude about 60 miles) at roughly 133,000 miles/hour (37 miles per second).  (“Shooting stars” or  “falling stars” are not stars at all!) Only very rarely do fragments reach the ground.

If you wish to view the meteor shower, it’s best to do so for at least half an hour (but an hour or longer is better). Try to get as far away from city lights as possible. The Perseids are known for having many bright and fast meteors that should be visible even in a somewhat light-polluted sky, though you’ll see many more from a darker location. *NO* binoculars or telescopes are needed; just look at the sky with your unaided eyes after getting dark-adapted (this can take up to 15 minutes). Choose a wide-open sky, without buildings or trees in the way. Dress warmly, and pack a hot beverage if you want to. Bug spray might be useful, too, depending on where
you are. You should lie down on a mattress, sleeping bag, or reclining lawn/deck chair for greater comfort, if you wish.

Looking anywhere in the sky is fine, but straight up often has the darkest sky. Views to the northeast should provide the most meteors, though their streaks will be shorter than if you look elsewhere. If you have clear and dark skies, you might see 20-40 meteors per hour. (The media often report 100 per hour, but that’s from the darkest locations, with a completely clear and unobstructed sky, at the shower’s peak intensity.)

There are many useful references with additional information and viewing tips, etc.; type “Perseid meteor shower 2024” in your favorite search engine. See, for example,
https://www.space.com/32868-perseid-meteor-shower-guide.html .
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A few years ago, some students emailed me, asking for advice regarding good locations from which to view the Perseid meteor shower and other celestial events in the San Francisco Bay Area. You want to be in as dark a location as possible, far from city lights, with no fog — but this obviously depends on how far you’re willing to drive. Here are some suggestions.

Above Berkeley, Grizzly Peak Blvd. could be reasonably good, though you’re not far from the city and also might not be above the fog. Ditto for Inspiration Point along Wildcat Canyon Road, on the border of Berkeley and Orinda. Other locations in Tilden Park could also be good, except for the darn marine layer (fog). You could just see how things go and have a backup plan, if you’ve got transportation.

To get away from the fog, I suggest driving inland as far as necessary. Mt. Diablo State Park near Walnut Creek should be clear and reasonably dark. If you’re willing to go farther, then Altamont Pass off of highway 580 (east of Livermore) will almost certainly be clear. For darker skies, head to the central valley, but not near big cities like Tracy or Manteca. If you really don’t mind driving far, then go to the Sierra foothills — the Auburn area along Highway 80 (but not in Auburn itself), or the Pollack Pines area along highway 50, or even farther into the mountains than these two locations (Lake Tahoe should be great!).

Roughly 1.5 hours from Berkeley, Pt. Reyes National Seashore is a really dark location, but I worry about the fog hugging the coastline and blocking your view of the sky. You might do better stopping somewhere along the way, such as near Olema or other locations along Lucas Valley Road. Or, you could consider going south instead of north — say, to the San Juan Bautista area (e.g., Fremont Peak, if it’s open). Another possibility is Mt. Hamilton Road (highway 130) toward Lick Observatory east of San Jose — but if the parking lot at the summit itself is closed, you’ll need to stop elsewhere along the way (and be really careful: the road is narrow, the drops
off the sides are steep, and there’s mostly no guard rail).

Some years ago, my kids and I were camping at the China Camp State Park campsite (San Rafael, CA). From the parking lot I got a great view of Comet NEOWISE, but this site would be pretty good for the Perseid meteor shower, too — it’s reasonably dark, and the hills to the west tend to keep the coastal fog away. You could instead be on the road next to the campsite parking lot, if they don’t let you in (the gate gets locked).

But even if you can’t travel to a really dark location, I encourage you to look for Perseid meteors — you should be able to see the occasional really bright ones even from a relatively urban location. Just find as dark a region as you can, such as a big park, and don’t position yourself near street lamps, etc.

Good luck!

Alex Filippenko

Early Tuesday morning, November 8 (i.e., Monday night, November 7), there will be an “Election Day” total lunar eclipse (when the Moon goes into Earth’s shadow) visible from North America. Weather permitting, everyone on Earth’s dark (night) side will be able to see it. No optical aid is needed — just use your eyes (though the view through binoculars should be interesting as well). Here’s some useful information; more details can be found at the end of the message.

We will be on Standard Time by Monday (switching from Daylight Time this Saturday night, Nov. 5). Unlike the case in a total *solar* eclipse, the lunar eclipse will occur simultaneously from any location where it is visible. However, you have to adjust for different time zones. Here are the relevant times (all are Tuesday early morning — that is, Mon. night after midnight):

Partial eclipse begins: 1:09 am PST,
                        2:09 am MST,
                        3:09 am CST,
                        4:09 am EST.

Total eclipse begins:   2:16 am PST,
                        3:16 am MST,
                        4:16 am CST,
                        5:16 am EST.

Total eclipse ends:     3:42 am PST,
                        4:42 am MST,
                        5:42 am CST,
                        6:42 am EST.

Partial eclipse ends:   4:49 am PST,
                        5:49 am MST,
                        6:49 am CST,
                        7:49 am EST.

(Subtract 2 hours from the above times, if in Hawaii.)

The time of sunrise (and thus moonset, since the full Moon will be opposite the Sun in the sky) depends on where you are in your time zone and also on your latitude — but *roughly* 6:40 am for much of the USA. So, from the eastern USA, the *total* eclipse ends around the time of sunrise, in a very bright sky. The rest of the USA can watch the entire total eclipse in dark skies. Over most of the USA, Mexico, and Canada, the Moon will be high in the sky throughout the eclipse (especially during the first partial phases and totality). However, as seen from the east coast, you’ll need a relatively low, clear western horizon.

The eclipse will also be visible from Australia, New Zealand, Siberia, and much of Asia, though it will be on Tue. night with the Moon in the east (not Tue. morning with the Moon in the west, as in N. America). See the attached map, courtesy Dominic Ford from in-the-sky.org . You can also consult the excellent website https://www.timeanddate.com/eclipse/lunar/2022-november-8 for a detailed map and to see whether the eclipse will be visible from a specific location (put your location in the “Eclipse Lookup” box on the right-hand side of the web page). Another good website is
https://earthsky.org/astronomy-essentials/total-lunar-eclipse-nov8-2022/ .

Totality will last about 1 hour 26 minutes, a relatively long total lunar eclipse (because part of the Moon will pass near the center of Earth’s shadow); if you include the partial phases, it lasts 3 hours 40 minutes. In case of clouds, rain, or snow, don’t give up hope (unless the forecast is truly hopeless)! The long duration of the eclipse means that you might occasionally get a good view of the Moon through a break in the clouds.

Wishing you clear skies during the night of November 7/8, 2022,

Alex

On the night of Wednesday, July 13, take a look at the full moon, a “supermoon.” Since it is closest to Earth in its elliptical orbit, the moon will look 14% larger and 30% brighter than when it is farthest from Earth (but only 7% larger and 15% brighter than an average full moon) — nice to see, though not the big deal that the press often makes of supermoons (they typically occur a few times per year). The view will be nearly as good on Tuesday and Thursday nights, in case Wednesday isn’t convenient for you or clouds are forecast.

What IS a big deal, though, is the first full-color, ”real science” image from the James Webb Space Telescope (JWST), released on Monday and attached here. It’s truly stunning! Showing a patch of sky just the size of a grain of sand held at arm’s length, it reveals thousands of distant galaxies — gravitationally bound collections of billions of stars (like the Milky Way Galaxy). This is the ”deepest” image of the Universe ever obtained, meaning that it shows the faintest and among the most distant objects ever seen, and it took 12.5 hours of observing at different wavelengths (colors of light) primarily in the infrared (longer wavelengths than visible light — what we often refer to as heat radiation, like from glowing coals).

The image is centered on a massive cluster of galaxies known as SMACS 0723, about 4.6 billion light years away (meaning that the light we are now seeing left those galaxies roughly when Earth and our Solar System was being formed!). It has a giant galaxy in the middle that’s gradually gobbling up other, smaller galaxies in the cluster. Surrounding the cluster are more-distant galaxies, some perhaps more than 13 billion light years away. Many of them are magnified in brightness and distorted into arc shapes because of the ”warping” of space (and time) caused by the massive cluster and predicted by Einstein’s theory of gravity (the general theory of relativity) — an effect called ”gravitational lensing.” The beauty and grandeur of this image are mind-boggling — as is the amount of information in it. (By the way, don’t pay attention to the few objects with six spikes coming out of them — these are stars in our own Milky Way Galaxy, and the spikes are a ”diffraction pattern” produced by the 18 hexagonal segments of JWST’s main mirror. They don’t appear in the images of faint, distant, fuzzy galaxies.)

On Tuesday, July 12, NASA’s main press conference about the first results from JWST will take place, and I encourage you to watch it (or read about the findings online, since you may receive this message too late — apologies). Opening remarks will be at 6:45 am PDT, and four new images will be shown and discussed in succession starting at 7:30 am PDT. There will be a news conference at 9:30 am PDT with more details about the images. Here’s a brief summary.

(1) The Carina Nebula is a cloud of gas and dust 7500 light years away (a light year is 6 million million miles) that can be thought of as a stellar nursery (in which stars have recently been born and are still being born). Many of those stars are very massive and hot. Our own Solar System formed about 4.6 billion years ago from a cloud similar to (but almost certainly much smaller than) this one.

(2) WASP-96b is a planet orbiting another star with a period of only 3.4 days, about half the mass of Jupiter and 1150 light years away from Earth. Its infrared spectrum will be shown, possibly revealing whether the planet has an atmosphere. In future studies of this type, astronomers hope to detect possible biosignatures (such as oxygen and methane) in the atmospheres of exoplanets.

(3) The Southern Ring Nebula is a ”planetary nebula” — gas that was gently ejected by a dying central star and is now glowing by a process similar to fluorescence (the central star is hot, and the UV light that it emits ionizes the surrounding cloud of gas, which then glows). It is about 2000 light years from Earth. Our own Sun will produce a similar object in about 7 billion years — so this is a sneak preview of its future. (“Planetary nebula” is actually a misnomer … the object only looks vaguely like a planet.)

(4) Stephan’s Quintet is a famous group of five galaxies, four of which are at nearly the same distance from Earth (about 290 million light years) and gravitationally interacting with each other in a cosmic dance. (The fifth galaxy is unrelated, and just happens to be along the same line of sight.) There might be a side-by-side comparison of what the Hubble Space Telescope records at visible (optical) wavelengths and what JWST detects in the infrared.

These promise to be amazing images and results! I’m absolutely thrilled that JWST is working correctly. Honestly, a year ago I had serious doubts that the mission would be successful, given the 340+ potential single-point failures. Kudos to NASA and all the people involved in the planning, construction, launch, unfolding, and commissioning of JWST!

I’m looking forward to getting JWST data in the coming year, for two approved studies regarding exploding stars (supernovae) — we are trying to see how much dust they form in the ejected gases. Some of this dust much later becomes incorporated into giant clouds of gas and dust like the Carina Nebula, forming new stars and planetary systems. Exciting stuff, indeed!

With best wishes,

Alex

P.S. Let me also alert you to a press release that my team sent out on Monday, regarding observations of the nearest known example of a star that was shredded, or ”spaghettified,” after approaching too close to a supermassive black hole at the center of a galaxy:
https://news.berkeley.edu/2022/07/11/the-ultimate-fate-of-a-star-shredded-by-a-black-hole/

This study was led by one of my graduate students, Kishore Patra. I’ll provide some more details (via email) later, after we compose and release another press release about a different study we’ve completed… but I want to keep this message focused on the JWST results.

Here is an interesting celestial sight that will be visible in the early morning this week in mid-June 2022.

Five naked-eye planets arc across the sky from east to west in the correct order of increasing distance from the Sun: Mercury (low above the eastern horizon), then very bright Venus, followed by Mars (looks reddish orange), Jupiter (bright), and Saturn. Such a “planetary parade” with all 5 planets visible *simultaneously* last occurred 18 years ago, and I think it won’t happen again until around 2100 (I might be wrong about this, but the configuration is quite rare in any case). To top it off, on the early morning of June 24, the waning crescent Moon will appear between Venus and Mars — representing Earth (since the Moon orbits us) at its proper place in the celestial lineup.

If you want to include Mercury, the best time to view this spectacle will be about 45 minutes before local sunrise: late enough in the night that Mercury will have had a chance to rise higher above the horizon, but not so late that the sky will be too bright because of the approaching sunrise. Binoculars could help you spot Mercury (or, use an App such as Sky Tonight, Star Walk 2, or SkyView). To see Mercury, you’ll need a very low, clear eastern horizon (i.e., no buildings, trees, hills, etc. in the way), but the other planets will be much easier to see in the southeast sky (and south, for Saturn).

This week, Mercury’s apparent separation from the Sun is decreasing, so the sooner you look (e.g., Sunday or Monday, June 19 or 20), the easier it will be to see Mercury — but try to also view the sky 45 minutes before sunrise on June 24, when the crescent Moon will join the arc between Venus and Mars.

I attach two diagrams: one from Sky & Telescope magazine showing the planets among the constellations, the other from timeanddate.com showing a simulated view from New York City at 4:40 am EDT on June 24.

Of course, although these planets *appear* close together in the sky, they are actually separated by up to hundreds of millions of kilometers; Jupiter and Saturn are 5 and 10 times farther from the Sun than Earth is, for example.

Wishing you clear skies,

Alex

 On Sunday evening/night, May 15, there will be a total lunar eclipse (when the Moon goes into Earth’s shadow). Weather permitting, everyone on Earth’s dark (night) side will be able to see it. The eclipse will occur in the eastern evening sky, shortly *after* sunset, as seen from the western continental United States and western Canada. It will be high in the sky at various times around the middle of the night in the eastern United States and Canada, Mexico, Central America, and South America. The total eclipse will not be visible from Hawaii, but the Moon will be partially eclipsed at moonrise (which occurs at sunset). In Spain and western Africa, the total eclipse will be visible before moonset in the western morning sky (Monday, May 16), shortly before sunrise. See the attached map, courtesy Dominic Ford from in-the-sky.org. Also, consult the excellent website https://www.timeanddate.com/eclipse/lunar/2022-may-16 for a detailed map and the ability to see whether the eclipse will be visible from a specific location (put your location in the “Eclipse Lookup” box on the right-hand side of the web page).

Totality will last about 1 hour 24 minutes, a relatively long total lunar eclipse (because part of the Moon will pass through the center of Earth’s shadow). Unlike the case in a total *solar* eclipse, the lunar eclipse will occur at the same time (after adjusting for time zones) from any location where it is visible. No optical aid is needed — just use your eyes (though the view through binoculars should be interesting as well).

Here are the  relevant times in San Francisco, CA; adjust for your time zone if you will be away from Pacific Daylight Time (PDT). (For example, mid-eclipse will be at 12:11 am EDT on May 16, as viewed from the USA’s east coast that’s Sunday night, but technically Monday early morning.)

Partial eclipse begins:   7:27 pm PDT Sunday, May 15  (below the eastern horizon)
Moonrise:   8:06 pm PDT  (You will need a very clear, low, eastern horizon to see it.)
Total eclipse begins:   8:29 pm PDT
Mid-eclipse:   9:11 pm PDT
Total eclipse ends:   9:53 pm PDT
Partial eclipse ends:   10:55 pm PDT

“Prime time” (total eclipse) will be 8:29-9:53 pm PDT. The Moon will be east, low over the horizon, shortly after it rises; try to avoid obstructions like mountains, buildings, and trees. The farther east you are in the continental United States, the farther above the horizon the Moon will be.

Again, for more information see https://www.timeanddate.com/eclipse/lunar/2022-may-16 .
Another good website is https://earthsky.org/astronomy-essentials/total-lunar-eclipse-may16-2022/ .

Wishing you clear skies during the night of May 15/16, 2022,

Alex

*****

Additional details:

The Moon doesn’t appear completely dark during a total lunar eclipse because some sunlight goes through Earth’s atmosphere and is bent (refracted) toward the Moon, and then it bounces off the Moon back toward us. But the Moon’s color generally appears some shade of yellow, orange, or even red because the light that reaches it has been filtered by Earth’s atmosphere, preferentially getting rid of the violet, blue, and green colors — just as in the case of the setting or rising Sun, which looks some shade of yellow, orange, or red, depending on the amount of particular matter (such as smoke) in the atmosphere. I expect that on May 15/16, the Moon will look pretty dark (though still orange/red) at mid-eclipse, because it will be deep in Earth’s shadow.

Also, on May 15/16 the full moon will be a little closer to Earth than average in its elliptical orbit and therefore look a bit bigger — a “Super Moon” (or “Supermoon”). But in my opinion, this is often exaggerated by the press; though the Moon isnearly at its closest to Earth in its elliptical orbit, even the best Super Moon looks only slightly bigger (6-7%) and brighter (12-14%) than an average full moon. Also, “Super Moons” are pretty common; in fact, there are three in 2022. Since the totally eclipse Moon can appear reddish orange, it is sometimes called a “Blood Moon,” so this particular eclipse will be a “Super Blood Moon.”

Note that during the partial phases, Earth’s shadow on the Moon looks distinctly curved. This is *always* the case during a lunar eclipse, and it was one of the many pieces of evidence that the ancients used to conclude Earth is round, not flat.

In the above list of times, I didn’t include the “penumbral” eclipse, when Earth blocks only *part* of the Sun as seen from the Moon; the full moon will look slightly fainter during the penumbral eclipse, but this effect is hard to notice and isn’t very interesting. It begins at 6:32 pm PDT (before moonrise in the PDT time zone) and ends at 11:50 pm PDT.

I’d like to alert you to a good opportunity to see the best comet of 2021 this weekend: Comet Leonard. Feel free to pass this information to your family and friends, if you wish.

A comet is a ” dirty iceball” (or an ” icy dirtball” — depending on the relative amounts of ice and dust) that comes from the deep freeze of the outer Solar System, beyond the orbit of Neptune. It heats up as it gets closer to the Sun, and the ices sublimate, becoming gas. This releases a cloud of dust that becomes visible by reflecting sunlight; the ” coma” of dust surrounds the nucleus, and the tail points roughly away from the Sun. The gas can also glow, and it points directly away from the Sun.

Comet Leonard, the brightest comet of 2021, has now conveniently moved from the morning sky to the evening sky, and will be very close to the brightest planet (Venus) the next few nights, making it easier to find. In clear, dark skies with a low southwest horizon, the comet’s nucleus might be visible to the unaided eye as a faint and fuzzy ”star.” You are much more likely to see it through binoculars; this will reveal the coma and perhaps also the tail. Photographs obtained with a digital camera mounted on a tripod will reveal more of the coma and tail (typical exposure time 4-20 seconds). You can find many excellent photos of the comet online (e.g., https://earthsky.org/astronomy-essentials/comet-leonard-might-become-2021s-brightest-2022/). After passing closest to the Sun on January 3, 2022, the comet will be ejected from our Solar System.

To find Comet Leonard, look to the southwest shortly after sunset in a darkening sky — around 5:20-5:30 pm (local time) would probably be best. It will be a little below Venus (the brightest object in the southwest sky) on the evening of Friday, December 17; see the attached chart (made by Eddie Irizarry using Stellarium software). On Saturday, December 18, it will be a little below and to the left of Venus, and on Sunday, Dec. 19, it will be farther to the left of Venus (and still a little below). Slowly scan that part of the sky while looking through binoculars. You’ll need to have a clear, low southwest horizon, not blocked by trees, hills, buildings, or other obstructions. Beyond Dec. 19, the comet could still be visible (progressively farther to the left of Venus), but it is expected to fade.

Good luck, clear skies, and happy holidays,

Alex