Thomas was gracious, gregarious, and incredibly generous with his time and ideas. He was a true gentleman and a brilliant scientist. Thomas was the dream collaborator, skilled at communicating complex concepts and providing insightful and thoughtful feedback. His positive outlook on life was contagious and meeting with him was always a delight. Thomas has left us far too soon, but what an indelible personal and professional legacy he leaves behind. My sincerest condolences to Yhasmin and his family.

I remember happy Thomas when running downhill the Berg Rigi in Switzerland few years ago. He enjoyed being outdoor as much as pushing forward frontiers of science from behind his computer. The true pioneer in all his being and doing!

Such a sweet man! Gentle, humble and kind. In his short life Thomas clearly left his mark in the hearts all who knew him and in his relatively brief career he has made an indelible mark as well. We will miss that contagious smile and the sharing of ideas, stories, and a beer. I know we all feel his premature loss deeply. 
Thanks to all who have shared your memories and photos, it’s both sad and wonderful to see. 
My sincere condolences to Yhasmin, his brother and father.

Every time I interacted with Thomas I was left with this singular impression: the man is truly awesome. What a loss! My heart goes out to Yhasmin and Thomas' family. RIP my friend.

I am deeply saddened to hear of Thomas Hilker’s passing. He was a wonder. It’s not often that you get to watch a young person develop from student and post doc to one of the very best scientists in the field even surpassing his mentors! He is gone too soon. I am grateful for his time on this Earth and what he has done for us. A while ago, NASA had a mission statement that read, “To understand and protect the home planet”. Many of us deeply believed in this and Thomas did it naturally. He is a hero for Earth.

Thomas was a delight to know - cheerful, kind, forward-thinking and optimistic. He will be very much missed by all whom he touched - colleagues, students and friends. May Yhasmin, his family, and all who knew him be blessed by his memory.

I will miss Thomas dearly. I would see Thomas once or twice a year at a conference or a meeting, and I knew that each time I would be greeted by his wide smile and cheerful presence. As I entered the realm of remote sensing science and sometimes felt nervous around leaders in the field, Thomas always made me feel welcome, treated me as an equal colleague, and bolstered my spirit. Thomas' legacy will continue both as a leader in his field and as a dear friend to so many.
My sincere condolences to Yhasmin and family.

Thomas, you were an amazing, hugely talented scientist, but also a brilliant friend and colleague. I'll never forget my year working with you at UBC and your never-failing kindness, generosity and humour, from the first day when you picked me up at the airport and through all the times since when I've been lucky enough to see you - made that time even more special. You will be deeply missed but not forgotten. My thoughts and sincere condolences are with your family and Yhasmin.

Thomas will be missed around the world - we will miss his insight and dedication to research and we will miss out on discoveries yet to come.

I know that all who knew Thomas, loved and respected him and are shocked and saddened by his passing. At this point, it is difficult for us to comprehend the meaning and purpose of this tragic event. But if any one life can have meaning, Thomas’ life brought joy and enlightenment to all who worked with him as a scientist. HIs selfless contributions to understanding the Earth are already substantial and over his career would have been enormous. We hope to follow in his footsteps to carry on the work he started.

I had known Thomas nearly 10 years, and In my three years working side by side with him at Goddard. I and other colleagues at Goddard developed deep friendships based on common purpose and understanding of what needed to be achieved scientifically and how to get there. We developed an entirely new approach to measuring the surface-atmosphere energy, water and carbon exchange from both tower and satellite. Without Thomas these important contributions would have never been possible. I am very proud of the work he and I did together and the work he continued with Yhasmin and others after leaving Goddard. I know he was looking forward to continuing this into the future.

Thomas was a fantastic scientist, a great colleague, and a super friend. His brilliant creativity and perseverence were matched only by his sense of humor and his smile. I always looked forward to field work with him when we were doing our Barn Tower project together at Harvard Forest, and in more recent years it was always wonderful to catch up with him at AGU.

Thomas you will be missed. My deepest condolences to your family and loved ones.

My sincere condolences to the family, to Yhasmin and to all of those who were close friends to Thomas

We will miss you, Thomas. A one-of-a-kind researcher, colleague and most importantly, person. Know that he left a lasting positive impact on the world. Condolences to his family and friends - you are in our thoughts and prayers.

My sincere condolences.

We were shocked and so deeply saddened by this news. A brilliant mind, analytics wizard, prolific scholar, keen scientist and passionate researcher making a real difference on important matters. He made a deep mark in Canada, receiving the Canadian Remote Sensing Society National Best Ph.D. Thesis Award at our national conference in 2009 for his research supervised by Nicholas Coops at UBC. So much after that, and so much ahead past 2016 yet cut short. Best of all a fine character, a person of high integrity, collegiality, humour, and a dear friend. 

Our deepest condolences to Yhasmin and everyone in Thomas’ family.

Derek Peddle – University of Lethbridge - Canada

I was (and still am) heartbroken that you have left us, and so suddenly. A light has gone out, and the world will not be the same without you in it. I am a better person and scientist from having worked and shared good times with you. I will always remember your amazing enthusiasm, humour and incredible passion for science. You were quite simply a star, and I will miss you terribly. Sending heartfelt condolences to Yhasmin and family at this hugely difficult time xx

My most sincere condolences. Thomas will be missed.

Thomas was the first person I talked from OSU. I still can vividly remember the first time we talked via Skype. He was the person who put me in connection with awesome folks at OSU. I still cannot believe this misfortune happened on such a young and energetic person. But his distinguished achievements in academia and innovative ideas will be admired and continued by peers.

Too shocked at the death of Thomas Hilker.
He is a great scientist at his young age. Still remember the communication about the multi-angle remote sensing and image fusion. RIP.

Fond memories of dinner and discussions with Thomas on the coast in Recife - such a great person who will be greatly missed.

It was always a pleasure to run into Thomas. He was a wonderful person and a great scientist. Such a terrible loss.

Jeannie and I only knew Thomas socially, as part of our close knit cul-de-sac group here in Corvallis OR. We traded enjoyable evenings with Thomas and Yhasmin and loved their company. It was a shock to all of us when we learned of his sudden medical event and subsequent passing. I can only pay him the highest complement I know, he was a gentleman. From his warmth to his humor, he was a delight. He was taken from all of us far too soon. Our hearts and love go out to Yhasmin and Thomas' family.

Thomas was such a rare person in our world. Selfless, brilliant and an all-around great man. This news is such a shock. While we never worked together, I always enjoyed reviewing his work and can only imagine what could have been. This is tragic news.

Thomas was a dear friend and stellar colleague. We were sad when he left OSU this summer, and didn't know that was the last time we would see him. His engaging smile and gentle spirit will be remembered forever. My heart goes out to his family. Rest in peace, Thomas.

It was in 2004 when Thomas first made contact with Nicholas Coops and I. Thomas had lined up Nicholas to supervise his PhD and I was brought on to co-supervise. From that point on, things were never the same! Thomas was Nicholas' first PhD. Imagine having to follow that! Thomas managed to take on every challenge with such confidence and grace. Never did he seem flustered. Quietly and efficiently things just got done, and done well. While Thomas had obvious abilities as a scientist, with equal ease he also gathered many friends, all of whom he managed to make feel special. Student, colleague, and friend - Thomas will be sorely missed.

We are of the 13th Place gang in Corvallis, Oregon. Thomas was a very wonderful part of our get-togethers, always a great smile.
We lived 1 door down from Thomas & would walk our dogs together at times. Yes Jazzy and Molly, Thomas would get the biggest smile when we would talk about Jazzy. This has all been like a very bad dream, such a terrible loss to all who knew Thomas. RIP our dear friend.

Jenny & John Sullivan

Thomas made a huge impact on those who were lucky enough to work with him. In addition to having one of the keenest minds in Earth science, he was one of the friendliest and most gregarious people you'd ever meet. I'm glad that he was able to spend a few years at GSFC, and we'll all miss him terribly.

This is such a sad loss. What a wonderful and gifted person. Thomas was an amazing scientist as well as a bright light of a human being... full of creative ideas, positive vibes, radiant smiles and kindness. He was a friend and colleague who I will really miss.

Thomas was, of course, a gifted PhD student.

Hard working, polite, respectful and efficient. He completed his PHD in 3 years, a record, as well as publishing 6 papers. He quickly out-paced his supervisor. During that time as a student he spent what time he could outdoors, learning about the trees, forests and fluxes. Indoors it was coding, databasing (oh.. his beloved database!) and writing. A gifted combination of skills that served him well throughout his career.

Thomas was a lab-mates dream

He was up for a drink (or many), a hike, a party, and a joke. He was often the victim of having his screen backdrops changed when away from his desk. To cats, which Thomas didn’t have much time for, and often much worse. He was the first to pitch in, to organize, to clean up or to pay.

Thomas became a stellar scientist.

He approached environmental questions and challenges with vigor and zeal. He had an enormous curiosity and passion for science. He loved tinkering with equipment, field and spectral data collection, programming, modelling, simulation and writing; making him a true all-rounder. From Landsat to LiDAR he moved between technologies with ease as he researched important issues of our time.

Thomas was also a collaborators delight.

He was respective of other opinions, eager to share ideas and approaches, happy to slow down and explain ideas simply or speed up and jump to the answer. He recognized others contribution and knew science was a collaborative endeavor. He was loyal to those he worked with, and travelled the world building networks of colleagues, based on respect, and the love of science.

But most of all…..

Thomas was my friend.

Thomas was a shining light of humanity and an exceptional scientist. His passing is a loss to the world. My heartfelt condolences go out to his family.

Thomas will be missed in the College of Forestry. He was a wonderful, cheerful, and brilliant friend and colleague.

Thomas is one of a kind, a rare friend and colleague. I am deeply saddened by the loss of this unassuming man. His death came like a swift arrow. While Thomas was taken from us too soon, he will always be remembered for his creativity, candor, and his gentle and bright face. May his soul rest in eternal peace and may his family get the strength to bear the pain.