Nonprofit · EIN 33-0175263
PLANETARY SCIENCE INSTITUTE
Also known as SAN JUAN INSTITUTE
Tax-exempt · TUCSON, AZ 85719
Financials
| Year ended | Form | Revenue | Expenses | Net income | Total assets | Liabilities | Net assets |
|---|---|---|---|---|---|---|---|
| September 30, 2025 | 990 | $17,044,515 | $17,282,384 | -$237,869 | $4,777,031 | $1,542,642 | $3,234,389 |
| September 30, 2024 | 990 | $17,875,430 | $17,793,247 | $82,183 | $5,660,734 | $2,230,439 | $3,430,295 |
| September 30, 2023 | 990 | $17,937,228 | $17,620,401 | $316,827 | $6,331,149 | $3,045,591 | $3,285,558 |
Financial details: 990 for the year ended September 30, 2025
Revenue
- Contributions, gifts and grants
- $116,313
- Program service revenue
- $16,871,209
- Investment income
- $50,478
- Other revenue
- $6,515
Expenses
- Grants and similar amounts paid
- $0
- Compensation of officers, directors and key employees
- $771,596
- Other salaries and wages
- $9,416,374
- Salaries, compensation and benefits (total)
- $13,129,275
- Professional fundraising fees
- $0
- Legal fees
- $18,532
- Accounting fees
- $40,000
- Occupancy
- $207,486
- Travel
- $462,870
- Depreciation
- $232,562
- Program services (functional)
- $15,392,652
- Management and general (functional)
- $1,887,548
- Fundraising (functional)
- $2,184
Balance sheet and other
- Total assets, start of year
- $5,660,734
- Total assets, end of year
- $4,777,031
- Total liabilities, end of year
- $1,542,642
- Net assets, end of year
- $3,234,389
- Land, buildings and equipment
- $959,947
- Net assets without donor restrictions
- $3,119,353
- Net assets with donor restrictions
- $115,036
- Gross receipts
- $17,044,515
- Employees
- 172
- Volunteers
- 4
- Year formed
- 1986
- State of legal domicile
- AZ
From the e-filed returns the IRS publishes as XML (latest three processing years; amended returns replace the original). PDF copies at the IRS.
Officers, directors and key employees
As listed on the 990 for the year ended September 30, 2025, highest compensation first.
| Name | Title | Hours / week | Compensation | Other / benefits |
|---|---|---|---|---|
| Mark V Sykes | CEO / Trustee (through April 2025) Trustee or director, Officer | 40 | $251,399 | $44,544 |
| Melinda Dyar | Senior Scientist Highest-paid employee | 40 | $241,888 | $33,582 |
| Maurizio A Ienna-Balistreri | CFO / Treasurer Officer | 40 | $186,274 | $51,135 |
| Nathaniel Putzig | Senior Scientist Highest-paid employee | 39 | $182,127 | $41,099 |
| Jonathan M Lilly | Senior Scientist Highest-paid employee | 40 | $183,994 | $25,663 |
| Eldar Z Noe Dobrea | Senior Scientist Highest-paid employee | 40 | $176,641 | $32,244 |
| Amanda R Hendrix | CEO / Trustee (effective May 2025) Trustee or director, Officer | 35 | $165,502 | $41,947 |
| Rebecca M Williams | Senior Scientist Highest-paid employee | 40 | $174,692 | $24,360 |
| Linda L Rueger | HR Director / Secretary Officer | 40 | $155,078 | $31,059 |
| Scott Fouse | Trustee/Board Chair Trustee or director, Officer | 5 | $0 | $0 |
| William Craig | Trustee/Vice Chair Trustee or director, Officer | 5 | $0 | $0 |
| William Hartmann | Trustee Trustee or director | 5 | $0 | $0 |
| Alison Nordt | Trustee Trustee or director | 5 | $0 | $0 |
| Arun Seraphin | Trustee Trustee or director | 5 | $0 | $0 |
| Dan Dumbacher | Trustee Trustee or director | 5 | $0 | $0 |
990 for the year ended September 30, 2024: 13 people
| Name | Title | Hours / week | Compensation | Other / benefits |
|---|---|---|---|---|
| Mark V Sykes | CEO / Trustee Trustee or director, Officer | 40 | $262,687 | $44,511 |
| Maurizio A Ienna-Balistreri | CFO / Treasurer Officer | 40 | $201,307 | $53,430 |
| Amanda R Hendrix | Senior Scientist Highest-paid employee | 40 | $196,113 | $52,564 |
| Catherine M Weitz | Senior Scientist Highest-paid employee | 40 | $178,166 | $40,147 |
| Nathaniel Putzig | Senior Scientist Highest-paid employee | 40 | $175,167 | $40,335 |
| Melinda Dyar | Senior Scientist Highest-paid employee | 30 | $183,202 | $25,648 |
| Eldar Z Noe Dobrea | Senior Scientist Highest-paid employee | 40 | $172,659 | $31,740 |
| Linda L Rueger | HR Director / Secretary Officer | 40 | $150,967 | $28,877 |
| Scott Fouse | Trustee/Board Chair Trustee or director, Officer | 5 | $0 | $0 |
| William Craig | Trustee/Vice Chair Trustee or director, Officer | 5 | $0 | $0 |
| William Hartmann | Trustee Trustee or director | 5 | $0 | $0 |
| Alison Nordt | Trustee Trustee or director | 5 | $0 | $0 |
| Arun Seraphin | Trustee Trustee or director | 5 | $0 | $0 |
990 for the year ended September 30, 2023: 13 people
| Name | Title | Hours / week | Compensation | Other / benefits |
|---|---|---|---|---|
| Mark V Sykes | CEO / Trustee Trustee or director, Officer | 40 | $251,857 | $41,205 |
| Maurizio A Ienna-Balistreri | CFO / Treasurer Officer | 40 | $192,384 | $46,484 |
| Bruce D Barnett | Senior Advisor / Secretary Officer | 40 | $188,630 | $38,512 |
| Amanda R Hendrix | Senior Scientist Highest-paid employee | 40 | $179,150 | $44,577 |
| Catherine M Weitz | Senior Scientist Highest-paid employee | 40 | $173,623 | $36,041 |
| Melinda Dyar | Senior Scientist Highest-paid employee | 32 | $180,820 | $25,304 |
| Scott H Robinson | Senior Scientist Highest-paid employee | 33 | $174,880 | $24,206 |
| Eldar Z Noe Dobrea | Senior Scientist Highest-paid employee | 40 | $167,365 | $29,287 |
| Scott Fouse | Trustee/Board Chair Trustee or director, Officer | 5 | $0 | $0 |
| William Craig | Trustee/Vice Chair Trustee or director, Officer | 5 | $0 | $0 |
| William Hartmann | Trustee Trustee or director | 5 | $0 | $0 |
| Alison Nordt | Trustee Trustee or director | 5 | $0 | $0 |
| Arun Seraphin | Trustee Trustee or director | 5 | $0 | $0 |
Address and contacts
- Address (IRS master file)
- 1700 E FORT LOWELL RD STE 106, TUCSON, AZ 85719-2395
- Principal officer (990 for 2024)
- Amanda R Hendrix, 1700 E Ft Lowell Rd No 106, Tucson, AZ 85719
- Signed the 990
- Maurizio Balistreri, Chief Financial Officer
- Phone
- (520) 622-6300
- Website
- www.psi.edu
- Return prepared by
- Keegan Linscott & Associates PC
Mission
The Planetary Science Institute exists to: enable our researchers to study the origin, characteristics, and evolution of planetary systems, including our solar system, Earth itself, and planetary systems around other stars; enable our educators to convey the resulting knowledge to the scientific community, and to the public at large to promote science education and science literacy; enable our people to use this knowledge to advance human activity in space and shape the future of robotic exploration of the solar system.
Program accomplishments
- The Planetary Science Institute (PSI) is an independent nonprofit science research and educational organization with an established record of excellence in solar system exploration, comparative planetology, science education and public outreach. PSI has scientists in more than 30 states, the District of Columbia, and other locations around the world. PSI scientists were awarded research grants and contracts to conduct diverse research and laboratory studies covering the Moon, Mars, asteroids, comets, meteorites, outer planet satellites, solar system dynamics, solar system origins, planets around other stars, and other areas. In the fiscal year ending September 30, 2025, PSI scientists operated instruments on NASA's Mars Science Laboratory and Juno missions and provided science team support for these missions along with NASA's Mars Reconnaissance Orbiter, Mars Perseverance Rover, Lunar Reconnaissance Orbiter, Psyche, New Horizons, and Europa Clipper missions and ESA's Mars Express. PSI scientists are developing insights into the origin of life, have discovered widespread water on the Moon, found a new population of impact craters on Venus and studied the possibilities for life on Saturn's moon Enceladus. They have improved our understanding of Earth's ionosphere and discovered potential ice-rich deposits in the equatorial region of Mars.The PSI Observatory continues to be used in the study of Jupiter's Io torus, the observation of comets, exoplanets and other bodies. PSI scientists support an instrument on the International Space Station to study the climate effects of dust (particularly from North Africa).PSI is responsible, as part of NASA's Planetary Data System, for archiving all mission data involving asteroids, comets and interplanetary dust and making it available to the general science community and public. PSI scientists engaged in public outreach through art, writing children's books, popular science books, and public lectures and broadcast events such as Discovery Channel and BBC specials.Expenses $15,392,652 · revenue $16,871,209
What it must file and when
IRS records say it files Form 990 or 990-EZ. Based on its last return; a smaller organization may file the 990-N. Its accounting year ends in September, so each return is due on the 15th day of the 5th month after that.
| Tax year | Year ended | Due | IRS public records |
|---|---|---|---|
| 2025 | September 30, 2026 | February 16, 2027 | Not due yet |
| 2024 | September 30, 2025 | February 17, 2026 | 990 on file |
| 2023 | September 30, 2024 | February 18, 2025 | 990 on file |
IRS record
- EIN
- 33-0175263
- Tax-exempt status
- 501(c)(3): Charitable, religious, educational or scientific organization
- Foundation status
- Publicly supported organization (170(b)(1)(A)(vi))
- Donations deductible (Pub 78)
- Public charity, 50% deduction limit
- Exempt since
- 1986
- Accounting year ends
- September
- Files
- Form 990 or 990-EZ
- Assets (IRS master file)
- $4,777,031
- Income (IRS master file)
- $17,044,515
Filing history
| Form | Year ended | Revenue | Expenses | Assets | Return |
|---|---|---|---|---|---|
| 990 | September 2025 | $17,044,515 | $17,282,384 | $4,777,031 | XML |
| 990 | September 2024 | $17,875,430 | $17,793,247 | $5,660,734 | XML |
| 990 | September 2023 | $17,937,228 | $17,620,401 | $6,331,149 | XML |
| 990 | September 2022 | $18,517,420 | $18,151,737 | $5,887,452 | IRS |
| 990 | September 2021 | – | – | – | IRS |
| 990 | September 2020 | – | – | – | IRS |
| 990 | September 2019 | – | – | – | IRS |
| 990 | September 2018 | – | – | – | IRS |
990-N: the IRS bulk file holds only the latest e-Postcard per organization; earlier years come from archived copies of that file since 2020 and can have gaps (the IRS e-Postcard search lists every one). 990, 990-EZ, 990-PF, 990-T: every e-filed return in the IRS e-file index since 2019; XML for the latest three processing years, amounts from the IRS Statistics of Income extracts before that. PDF copies and determination letters at the IRS (search EIN 33-0175263).
Questions about PLANETARY SCIENCE INSTITUTE
- What is the EIN of PLANETARY SCIENCE INSTITUTE?
- The employer identification number (EIN) of PLANETARY SCIENCE INSTITUTE is 33-0175263.
- Is PLANETARY SCIENCE INSTITUTE tax-exempt?
- Yes. The IRS lists it as tax-exempt under section 501(c)(3) since 1986.
- Are donations to PLANETARY SCIENCE INSTITUTE tax-deductible?
- Yes. It is listed in IRS Publication 78 (Public charity, 50% deduction limit).
- Which annual return does PLANETARY SCIENCE INSTITUTE file?
- Form 990 or 990-EZ. Based on its last return; a smaller organization may file the 990-N.
- When is the next return of PLANETARY SCIENCE INSTITUTE due?
- The return for tax year 2025 (the year ending September 30, 2026) is due February 16, 2027. Form 8868 extends it by six months; the 990-N cannot be extended.
- When did PLANETARY SCIENCE INSTITUTE last file with the IRS?
- The latest return in the IRS public files is the 990 for the year ended September 2025.
- Who is the principal officer of PLANETARY SCIENCE INSTITUTE?
- The 990 for the year ended September 30, 2025 names Amanda R Hendrix.
- Who are the officers and directors of PLANETARY SCIENCE INSTITUTE?
- The 990 for the year ended September 30, 2025 lists 15 people; 9 received compensation from the organization, the highest $251,399 (Mark V Sykes, CEO / Trustee (through April 2025)).
- How much revenue does PLANETARY SCIENCE INSTITUTE have?
- On its 990 for the year ended September 30, 2025 it reported revenue of $17,044,515, expenses of $17,282,384 and total assets of $4,777,031 at year end.
Other nonprofits in TUCSON
- TUCSON MEDICAL CENTER EIN 86-0137567 · last filed 990 for 2024
- EL RIO SANTA CRUZ NEIGHBORHOOD HEALTH CENTER INC EIN 86-0285857 · last filed 990 for 2025
- UNIVERSITY OF ARIZONA FOUNDATION EIN 86-6050388 · last filed 990 for 2025
- EPIDAURUS EIN 77-0418201 · last filed 990 for 2025
- VANTAGE WEST CREDIT UNION EIN 86-0120482 · last filed 990 for 2024
- COMMUNITY FINANCE CORPORATION EIN 86-0683138 · last filed 990-PF for 2025
- COMMUNITY FOOD BANK INC EIN 51-0192519 · last filed 990 for 2025
- PORTABLE PRACTICAL EDUCATIONAL PREPARATION INC EIN 23-7232227 · last filed 990 for 2025