Semantic Coherence: The Planetary Society – Signal Evidence & AI Readability

[H1] Advance space exploration
Learn about our mission to increase discoveries in our Solar System, elevate the search for life beyond our planet, and decrease the risk of Earth being hit by an asteroid.
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[H2] Featured Stories
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[H3] What would it be like to fly through Saturn’s rings?
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[H3] The best images from Artemis II
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[H3] 2026 Member Roundtable Tour
Space Policy & Advocacy
[H3] Save NASA Science Action Hub
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[H3] 84 NASA missions at risk under new proposal
Planetary Radio
[H3] Los Angeles Astronomical Society celebrates 100 years of looking up
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[H2] Find your place in space
Co-founded by Carl Sagan in 1980, The Planetary Society is a member-funded nonprofit organization dedicated to advancing space science and exploration through three core enterprises.
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[H3] Explore Worlds
Increase discoveries about the worlds of our Solar System and beyond.
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[H3] Find Life
Elevate the search for life as a space exploration priority.
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[H3] Defend Earth
Decrease the risk of Earth being hit by an asteroid or comet.This content is hosted by a third party (vimeo.com), which uses marketing cookies. Please accept marketing cookies to watch this video.Join Chief Ambassador Bill Nye and become a member of the world’s largest and most effective space advocacy movement.
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[H2] Featured Fundraising Campaign
[H3] SAVING NASA Science
Your donation powers our advocacy when it matters most.
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[H2] Space Policy & Advocacy
[H3] Where we stand on the issues
Mars sample return, increasing NASA science funding, advocating for NEO Surveyor, flexibility for Artemis procurement and partnerships, and elevating the search for life beyond Earth. Together we’re active in advancing space science and exploration.
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[H3] Become A Member
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[H3] Get More Space

[H1] Find your place in space
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Gift MembershipsShare the joy of exploration. Click here to explore our gift memberships.
Kids MembershipsClick here to learn more about The Planetary Academy for young explorers.
[H1] Find your place in space
When you become a member, you join our mission to increase discoveries in our Solar System and beyond, elevate the search for life outside our planet, and decrease the risk of Earth being hit by an asteroid.Carl Sagan co-founded this nonprofit for those who believe in exploration to take action together. Are you with us?
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Bill Nye, Chief AmbassadorThe Planetary Society
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[H2] Basic Benefits
Memberships across all levels receive the following basic benefits:Personalized membership card and social media donor badgeExclusive access to our online Member Community featuring live events, free classes, and moreSubscription to The Planetary Report magazine (choose digital or print)Member e-newslettersOpportunities to influence space programs through our advocacy campaignsInvitations to special events including Planetary Radio LiveYour name sent to space on select space missionsAccess to our exciting worldwide member travel programs
[H2] Membership Level Premiums
Click buttons below to review unique premiums for each membership level:
Explorer (Individual)With a membership of $4/mo or $50/yr, if you are new member, you will receive as a premium:Official member T-shirt in your choice of size
Explorer Family / DualFor two members in the same household. With a membership of $6/mo or $75/yr, new members will receive as a premium:Two official member T-shirts in your choice of sizesTwo personalized membership cardsUpgrading members will receive any premiums not included in their previous membership level.
MarinerWith a membership of $10/mo or $125/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinUpgrading members will receive any premiums not included in their previous membership level.
PathfinderWith a membership of $20/mo or $250/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinSpace Images: an awe-inspiring set of four 8x10 inch printsUpgrading members will receive any premiums not included in their previous membership level.
VisionaryWith a membership of $40/mo or $500/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinSpace Images: an awe-inspiring set of four 8x10 inch printsRecognition in the New Millennium Committee, the Society’s most prestigious donor recognition society, including name recognition in The Planetary Report and on planetary.orgExclusive advocacy teleconferences with Chief Advocate Casey Dreier and Chief Ambassador Bill NyePlanetary Society logo pen — made of 100% aerospace-grade real carbon fiberUpgrading members will receive any premiums not included in their previous membership level.
ScoutWith a membership of $80/mo or $1,000/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinSpace Images: an awe-inspiring set of four 8x10 inch printsRecognition in the New Millennium Committee, the Society’s most prestigious donor recognition society, including name recognition in The Planetary Report and on planetary.orgExclusive advocacy teleconferences with Chief Advocate Casey Dreier and Chief Ambassador Bill NyePlanetary Society logo pen — made of 100% aerospace-grade real carbon fiberSpace exploration calendarUpgrading members will receive any premiums not included in their previous membership level.
SurveyorWith a membership of $200/mo or $2,500/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinSpace Images: an awe-inspiring set of four 8x10 inch printsRecognition in the New Millennium Committee, the Society’s most prestigious donor recognition society, including name recognition in The Planetary Report and on planetary.orgExclusive advocacy teleconferences with Chief Advocate Casey Dreier and Chief Ambassador Bill NyePlanetary Society logo pen — made of 100% aerospace-grade real carbon fiberSpace exploration calendarOfficial sterling silver logo pinUpgrading members will receive any premiums not included in their previous membership level.
RoverWith a membership of $400/mo or $5,000/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinSpace Images: an awe-inspiring set of four 8x10 inch printsRecognition in the New Millennium Committee, the Society’s most prestigious donor recognition society, including name recognition in The Planetary Report and on planetary.orgExclusive advocacy teleconferences with Chief Advocate Casey Dreier and Chief Ambassador Bill NyePlanetary Society logo pen — made of 100% aerospace-grade real carbon fiberSpace exploration calendarOfficial sterling silver logo pinPin, patch, and medallion set for LightSailUpgrading members will receive any premiums not included in their previous membership level.
PioneerWith a membership of $825/mo or $10,000/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinSpace Images: an awe-inspiring set of four 8x10 inch printsRecognition in the New Millennium Committee, the Society’s most prestigious donor recognition society, including name recognition in The Planetary Report and on planetary.orgExclusive advocacy teleconferences with Chief Advocate Casey Dreier and Chief Ambassador Bill NyePlanetary Society logo pen — made of 100% aerospace-grade real carbon fiberSpace exploration calendarOfficial sterling silver logo pinPin, patch, and medallion set for LightSailOfficial gold-plated logo pinAcknowledgement on Planetary Radio broadcastUpgrading members will receive any premiums not included in their previous membership level.
VoyagerWith a membership of $1,650/mo or $20,000/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinSpace Images: an awe-inspiring set of four 8x10 inch printsRecognition in the New Millennium Committee, the Society’s most prestigious donor recognition society, including name recognition in The Planetary Report and on planetary.orgExclusive advocacy teleconferences with Chief Advocate Casey Dreier and Chief Ambassador Bill NyePlanetary Society logo pen — made of 100% aerospace-grade real carbon fiberSpace exploration calendarOfficial sterling silver logo pinPin, patch, and medallion set for LightSailOfficial gold-plated logo pinAcknowledgement on Planetary Radio broadcastPostcards from Mars book and art-framed photograph autographed by author and Planetary Society board member, Dr. Jim BellUpgrading members will receive any premiums not included in their previous membership level.
New HorizonsWith a membership of $2,500/mo or $30,000/yr, new members will receive as a premium:Official member T-shirt in your choice of sizeOfficial member logo pinSpace Images: an awe-inspiring set of four 8x10 inch printsRecognition in the New Millennium Committee, the Society’s most prestigious donor recognition society, including name recognition in The Planetary Report and on planetary.orgExclusive advocacy teleconferences with Chief Advocate Casey Dreier and Chief Ambassador Bill NyePlanetary Society logo pen — made of 100% aerospace-grade real carbon fiberSpace exploration calendarOfficial sterling silver logo pinPin, patch, and medallion set for LightSailOfficial gold-plated logo pinAcknowledgement on Planetary Radio broadcastPostcards from Mars book and art-framed photograph autographed by author and Planetary Society board member, Dr. Jim BellPlanetariam, a three-dimensional planetary modelUpgrading members will receive any premiums not included in their previous membership level.
[H2] T-Shirt Sizes
New members and eligible membership upgrades receive our exclusive member t-shirt. This beautiful print by Thomas Romer of Chop Shop features strange and wondrous worlds of our Solar System and includes an illustrated, fact-filled digital guide.
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Below are sizing charts to help you select the best size. Measurement units are inches.
[H3] Men's T-Shirts
Please note that these are the product specifications of the t-shirts.SizeBody LengthBody WidthXS27.75"16.5"S28.75"18"M29.75"20"L30.75"22"XL31.75"24"2XL32.75"26"3XL33.75"28"4XL34"30"
[H3] Women's T-Shirts
Please note that for women's t-shirts, body length is measured from high point shoulder to finished hem at back and chest width is measured across the chest one inch below armhole when laid flat.SizeBody LengthChest WidthXS25.5"16.75"S26"17.75"M26.5"18.75"L27.25"20.25"XL28"21.75"2XL28.5"23.75"3XL29"25.75"4XL29"27.75"
[H3] As a Member, You Enjoy Special Privileges
Basic benefits include:personalized membership card and social media donor badgeexclusive access to our online Member Community featuring live events, free classes, and moresubscription to The Planetary Report magazine (choose digital or print)member e-newslettersopportunities to influence space programs through our advocacy campaignsinvitations to special events including Planetary Radio Liveyour name sent to space on select space missionsaccess to our exciting worldwide member travel programs
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When you first join at the Explorer level or higher, you'll receive our official Planetary Society T-shirt designed exclusively for members. Explore our membership levels to check out other cool space perks.
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All active members receive exclusive access to our online Member Community featuring live virtual events, free classes, opportunities to connect with fellow members, and more. Become a member today.
[H3] Testimonials
“I joined to support an advocacy group that educates the general public, voters, and decision makers on the importance of investment in space.”
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Sanmukh KuppannagariPlanetary Society Member“Being a member of The Planetary Society is like being a part of Starfleet Academy. We're helping to push the boundaries of space exploration to boldly go where no one has gone before.”
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Kellie R. GadekenPlanetary Society Member“Thanks to the support of Planetary Society members around the world, we're on the verge of breakthrough precision that will allow for new discoveries.”
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Dr. Debra FischerYale University astronomer and head of the 100 Earths exoplanet-hunting project at Lowell Observatory“We need to make sure that we have groups like The Planetary Society always engaged, always interested… I cannot tell you how important it is.”
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Jim BridenstineFormer NASA AdministratorThis content is hosted by a third party (youtube.com), which uses marketing cookies. Please accept marketing cookies to watch this video.“Star Trek is, of course, fiction. But its idea is very real and very important. It is this idea which The Planetary Society is devoted to and I believe they can help turn into a reality.”
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Gene RoddenberryStar Trek Creator
Become A Member
[H3] Questions?
We're excited to have you join and understand you may have questions. We've compiled answers to our Frequently Asked Questions and encourage you to contact us if you still have any outstanding questions.
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Certified Platinum Transparency. Give with confidence. The Planetary Society is incorporated as a 501(c)(3) non-profit organization in the United States.Together we'll advance space science and exploration!

[H1] Articles
AuthorAll
KeywordAllBill NyeBruce BettsCasey DreierKate HowellsRae PaolettaAsa StahlAll Articles
[H4] Current Missions
AkatsukiBepiColomboCuriosityExoMars Trace Gas OrbiterHayabusa2HubbleInsightInternational Space StationJunoLunar Reconnaissance OrbiterMars OdysseyMars Orbiter MissionMAVENNew HorizonsOSIRIS-RExVoyagerWISE and NEOWISE
[H4] Solar System
SunMercuryVenusEarthMarsJupiterSaturnUranusNeptuneSmall BodiesStories, updates, insights, and original analysis from The Planetary Society.
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The DownlinkNew asteroid discoveries, big changes at NASA, and breathtaking views of Saturn.
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Asa StahlSaturn’s rings are one of the most beautiful sights in the Solar System, but most of us have no idea what they look like up close.
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The DownlinkSpeeding up, slowing down, capturing amazing views, making discoveries — all thanks to planets.
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Asa StahlAn update in the search for alien life beyond the Solar System.
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Casey DreierRallying a rejection of proposed cuts to NASA, once again.
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The DownlinkA model Mars capsule flew through the air. Alien ships likely didn’t.
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Jack KiralyThe bill keeps NASA funding flat with the currently enacted budget, but reprioritizes funding levels across the agency, including a 17% cut to Science to offset increases elsewhere.
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The DownlinkHow things in space get their names, progress and awards for Saving NASA Science, and the human side of Artemis II.
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The DownlinkWith so many worlds to explore and so much to learn about our own, funding NASA is absolutely essential.
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Asa StahlHow much did Artemis II resonate with people — or glance off them?
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Asa StahlThe scientists behind threatened missions speak out.
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Jack KiralyThe 2026 Day of Action brought more than 130 space advocates from 34 states and the District of Columbia to the nation’s capital to advocate for space.
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The DownlinkCelebrate Earth Day by saving NASA Science.
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Casey DreierAn analysis of the latest President's Budget Request for NASA.
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Kate HowellsFrom a lunar feature named after a loved one to a planet named after a god, traditions and rules guide how we name things in space.
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Casey DreierArtemis II and the return of lunar spaceflight
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The DownlinkThe successful conclusion to Artemis II; the threat of termination to many other missions.
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Asa StahlProposed NASA cuts would reduce NASA’s workforce by thousands and cancel over 50 space missions.
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The DownlinkArtemis II brings us amazing views of Earth, the Moon, and the Cosmos beyond.
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Kate HowellsOur favorite images from humanity's return to the Moon.
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[H1] Support Planetary Society Projects
[H2] Your support can advance space science and exploration
[H3] SAVING NASA Science
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[H3] The Planetary Fund
Your support of The Planetary Fund powers our mission to explore worlds, find life, and defend Earth.
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[H3] LightSail
The Society’s dream of solar sailing came true with the successful test flight of our LightSail 1 spacecraft. LightSail 2 launched aboard the SpaceX Falcon Heavy rocket on June 25, 2019. Join the Extended Mission Team and support this historic project!
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[H3] Shoemaker Near-Earth Object Grant Program
The Planetary Society's Shoemaker Grant program supports amateur observers, observers in developing countries, and professional astronomers following up potentially hazardous asteroids.
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[H3] Planetary Radio
Each week, Planetary Radio visits with a scientist, engineer, project manager, astronaut, advocate or writer who provides a unique and exciting perspective on the exploration of our solar system and beyond.
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[H3] Membership & Giving
There's many ways to support The Planetary Society. Join thousands of fellow space enthusiasts from around the world who are advancing space science and exploration.