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National Capital Astronomers

About NCA

NCA logoServing science and society since 1937. The National Capital Astronomers (NCA) is a non-profit, membership supported, volunteer run, public service corporation dedicated to advancing space technology, astronomy, and related sciences through information, participation, and inspiration, via research, lectures and presentations, publications, expeditions, tours, public interpretation, and education. NCA is the astronomy affiliate of the Washington Academy of Sciences. We are also members of the Astronomical League, in fact NCA members helped form the Astronomical League a long time ago.

NCA has for many years published a monthly newsletter called Star Dust that is available for members. Besides announcement of coming NCA meetings and a calendar of monthly events Star Dust contains reviews of past meeting and articles on current astronomical events.

NCA is a very unusual astronomy organization. All are welcome to join. Everyone who looks up to the sky with wonder is an astronomer and welcomed by NCA. You do not have to own a telescope, but if you do own one that is fine, too. You do not have to be deeply knowledgeable in astronomy, but if you are knowledgeable in astronomy that is fine, too. You do not have to have a degree, but if you do that is fine, too. WE ARE THE MOST DIVERSE local ASTRONOMY CLUB anywhere. Come to our meetings and you will find this out. WE REALLY MEAN THIS!

Our Meetings

Monthly Meetings with Educational Presentations are Free and Open to the Public

NCA has regular monthly meetings September through June on the second Saturday of the month. Most meetings are held at the University of Maryland Astronomical Observatory in College Park, Maryland (directions/map).

Public transportation: Directions/maps to the UMD Observatory
Inclement weather: In case of severe weather (tornado/snow/impassable roads), a notice will be placed on the Observatory Website on the day of the meeting. (Be sure to refresh/reload the page to make sure you are seeing an updated page.)

Meeting Schedule for 2018-2019

Next Meeting Date: Saturday, 13 April 2019

7:30 pm at the University of Maryland Observatory on Metzerott Road.

Optimized Broadband Colors for Discriminating Earth-like Exoplanets

Speaker: Dr. Noam Izenberg, JHU-APL

Abstract: A three-color photometer, precisely pointed, with an angular resolution better than an arc-second, would enable us to distinguish Earth-like exoplanets from other rocky, gassy, or icy worlds - if we had the right three wavelengths, and the ability to block out the primary star's glare. Color-color discrimination of Earth-like planets has been sought for quite some time. Broadband filters would not enable measuring the fine spectral features that might indicate the presence of life, but would affordably provide precise overall indications of similarity to, or difference from, the one habitable planet we know.

We conducted an optimization exercise to arrive at a set of three broadband filters that reliably separate modeled Earth-like (hence possibly habitable) planets from other possible exoplanets. The optimized bands resemble the results of previous work for exoplanets and the solar system, but underscore the advantage of including UV wavelengths, and indicate their potential utility for exoplanet identification and/or discrimination, when used in concert with other exoplanet observations.

Bio: Noam Izenberg has been a planetary scientist at Johns Hopkins University's Applied Physics Laboratory since 1997, and has been involved in research and missions across the solar system and, recently, beyond. He's interested in the processes that change the appearance and compositions of planetary surfaces. From the solar wind and cosmic rays of "space weather" to the atmospheres, winds and waves of planetary weather systems, to impact craters and the internal processes of volcanism and tectonism, the surfaces solar system bodies are always evolving, and the different processes change the appearance of a surface in many different, and sometimes surprising ways. The processes at and below the surface, and how they affect the atmosphere (if any) of a body are critical to understanding how planets appear telescopically. Thus comparative planetology of our own solar system is an important tool for understanding the ever increasing menagerie of exoplanets we are finding. Dr. Izenberg has been an Instrument Scientist on the NEAR Shoemaker mission to the asteroid 433 Eros, and the MESSENGER mission to Mercury, and is the deputy chair of NASA's Venus Exploration Analysis Group. He is leading an Exoplanet Identifier Space Telescope (ExiST) study at APL.

Weather-permitting, there will be observing through the telescopes after the meeting for members and guests.


Join Us for Dinner Before the Meeting

Telescope-Making and Mirror-Grinding

Telescope-making and mirror-making classes with Guy Brandenburg at the Chevy Chase Community Center, at the intersection of  McKinley Street and Connecticut Avenue, NW, a few blocks inside the DC  boundary, on the northeast corner of the intersection, in the basement  (wood shop), on Tuesdays & Fridays, from 6:30 to 9:30 PM. For information visit Guy's Website  To contact Guy, use this phone #: 202-262-4274 or Email Guy.

Come See the Stars at Exploring the Sky 2019!

Exploring the Sky is an informal program that for over sixty years has offered monthly opportunities for anyone in the Washington area to see the stars and planets through telescopes from a location within the District of Columbia.
Sessions are held in Rock Creek Park once each month on a Saturday night from April through November, starting shortly after sunset. We meet in the field just south of the intersection of Military and Glover Roads NW, near the Nature Center. A parking lot is located next to the field.
Beginners (including children) and experienced stargazers are all welcome-and it's free!
Questions? Call the Nature center at (202) 895-6070 or check: Exploring the Sky @ Rock Creek. Download the flier!

Date Time Things of interest
6 Apr 8:30pm Winter constellations’ last gasp
4 May 9:00pm Mars, big dipper high
1 Jun 9:00pm Vega rising, Mars setting
6 Jul 9:00pm Moon, Jupiter, summer triangle, M13
10 Aug 8:30pm Moon, Jupiter, Saturn, M13, Andromeda
7 Sep 8:00pm Moon,Jupiter, Saturn, Vega
5 Oct 7:30pm Moon, Jupiter, Saturn in a row
2 Nov 7:00pm Moon, Pleiades, winter constellations
Exploring the Sky is a presentation of the National Park Service and National Capital Astronomers.

For NCA information by E-mail or phone

NCA Documents

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Updated by E. Warner on 8 April 2019.